diff --git a/core/modules/aggregator/lib/Drupal/aggregator/Plugin/block/block/AggregatorCategoryBlock.php b/core/modules/aggregator/lib/Drupal/aggregator/Plugin/block/block/AggregatorCategoryBlock.php
index aa1036c..4c2df27 100644
--- a/core/modules/aggregator/lib/Drupal/aggregator/Plugin/block/block/AggregatorCategoryBlock.php
+++ b/core/modules/aggregator/lib/Drupal/aggregator/Plugin/block/block/AggregatorCategoryBlock.php
@@ -62,9 +62,9 @@ public function blockSubmit($form, &$form_state) {
   }
 
   /**
-   * Implements \Drupal\block\BlockInterface::build().
+   * Implements \Drupal\block\BlockBase::blockBuild().
    */
-  public function build() {
+  public function blockBuild() {
     $id = $this->getPluginId();
     if ($category = db_query('SELECT cid, title, block FROM {aggregator_category} WHERE cid = :cid', array(':cid' => $id))->fetchObject()) {
       $result = db_query_range('SELECT i.* FROM {aggregator_category_item} ci LEFT JOIN {aggregator_item} i ON ci.iid = i.iid WHERE ci.cid = :cid ORDER BY i.timestamp DESC, i.iid DESC', 0, $this->configuration['block_count'], array(':cid' => $category->cid));
diff --git a/core/modules/aggregator/lib/Drupal/aggregator/Plugin/block/block/AggregatorFeedBlock.php b/core/modules/aggregator/lib/Drupal/aggregator/Plugin/block/block/AggregatorFeedBlock.php
index 58391d7..e902eb5 100644
--- a/core/modules/aggregator/lib/Drupal/aggregator/Plugin/block/block/AggregatorFeedBlock.php
+++ b/core/modules/aggregator/lib/Drupal/aggregator/Plugin/block/block/AggregatorFeedBlock.php
@@ -62,9 +62,9 @@ public function blockSubmit($form, &$form_state) {
   }
 
   /**
-   * Implements \Drupal\block\BlockInterface::build().
+   * Implements \Drupal\block\BlockBase::blockBuild().
    */
-  public function build() {
+  public function blockBuild() {
     // Plugin IDs look something like this: aggregator_feed_block:1.
     list(, $id) = explode(':', $this->getPluginId());
     if ($feed = db_query('SELECT fid, title, block FROM {aggregator_feed} WHERE block <> 0 AND fid = :fid', array(':fid' => $id))->fetchObject()) {
diff --git a/core/modules/block/block.module b/core/modules/block/block.module
index b1a5f52..31ef8db 100644
--- a/core/modules/block/block.module
+++ b/core/modules/block/block.module
@@ -515,7 +515,7 @@ function _block_get_renderable_block($element) {
   $block = $element['#block'];
   // Don't bother to build blocks that aren't accessible.
   if ($element['#access'] = $block->access()) {
-    $build = block_build($block);
+    $build = $block->build();
     if ($build) {
       if (isset($build['#title'])) {
         $element['#title'] = $build['#title'];
@@ -531,34 +531,6 @@ function _block_get_renderable_block($element) {
 }
 
 /**
- * Allows blocks to be altered after they are built.
- *
- * @param \Drupal\block\BlockInterface $block
- *   The block instance.
- *
- * @return array $build
- *   A renderable array of data.
- *   - #title: The default localized title of the block.
- *
- * @todo Move the alter invocation into a plugin method.
- * @todo Add specific examples of $id and $name below.
- */
-function block_build($block) {
-  // Allow modules to modify the block before it is viewed, via either
-  // hook_block_view_alter(), hook_block_view_ID_alter(), or
-  // hook_block_view_NAME_alter().
-  $id = str_replace(':', '__', $block->getPluginId());
-
-  $config = $block->getConfig();
-  $config_id = explode('.', $config['config_id']);
-  $name = array_pop($config_id);
-
-  $build = $block->build();
-  drupal_alter(array('block_view', "block_view_$id", "block_view_$name"), $build, $block);
-  return $build;
-}
-
-/**
  * Implements hook_cache_flush().
  */
 function block_cache_flush() {
diff --git a/core/modules/block/custom_block/lib/Drupal/custom_block/Plugin/block/block/CustomBlock.php b/core/modules/block/custom_block/lib/Drupal/custom_block/Plugin/block/block/CustomBlock.php
index f4d3375..29a7af9 100644
--- a/core/modules/block/custom_block/lib/Drupal/custom_block/Plugin/block/block/CustomBlock.php
+++ b/core/modules/block/custom_block/lib/Drupal/custom_block/Plugin/block/block/CustomBlock.php
@@ -90,9 +90,9 @@ public function blockSubmit($form, &$form_state) {
   }
 
   /**
-   * Implements \Drupal\block\BlockInterface::build().
+   * Implements \Drupal\block\BlockBase::blockBuild().
    */
-  public function build() {
+  public function blockBuild() {
     // Populate the block with the user-defined block body.
     return array(
       '#theme' => 'custom_block_block',
diff --git a/core/modules/block/lib/Drupal/block/BlockBase.php b/core/modules/block/lib/Drupal/block/BlockBase.php
index d1f0e40..5d9e1e8 100644
--- a/core/modules/block/lib/Drupal/block/BlockBase.php
+++ b/core/modules/block/lib/Drupal/block/BlockBase.php
@@ -21,6 +21,10 @@
   /**
    * Implements \Drupal\block\BlockInterface::settings().
    *
+   * Most block plugins should not override this method. To add additional
+   * settings or change the default values for setting, override
+   * BlockBase::blockSettings().
+   *
    * @see \Drupal\block\BlockBase::blockSettings()
    */
   public function settings() {
@@ -36,7 +40,7 @@ public function settings() {
   /**
    * Returns plugin-specific settings for the block.
    *
-   * Block plugins only need to implement this method if they override the
+   * Block plugins only need to override this method if they override the
    * defaults provided in BlockBase::settings().
    *
    * @return array
@@ -211,7 +215,8 @@ public function access() {
    *
    * Creates a generic configuration form for all block types. Individual
    * block plugins can add elements to this form by overriding
-   * BlockBase::blockForm().
+   * BlockBase::blockForm(). Most block plugins should not override this
+   * method unless they need to alter the generic form elements.
    *
    * @see \Drupal\block\BlockBase::blockForm()
    */
@@ -452,6 +457,9 @@ public function blockForm($form, &$form_state) {
   /**
    * Implements \Drupal\block\BlockInterface::validate().
    *
+   * Most block plugins should not override this method. To add validation
+   * for a specific block type, override BlockBase::blockValdiate().
+   *
    * @todo Add inline documentation to this method.
    *
    * @see \Drupal\block\BlockBase::blockValidate()
@@ -505,6 +513,9 @@ public function blockValidate($form, &$form_state) {}
   /**
    * Implements \Drupal\block\BlockInterface::submit().
    *
+   * Most block plugins should not override this method. To add submission
+   * handling for a specific block type, override BlockBase::blockSubmit().
+   *
    * @todo Add inline documentation to this method.
    *
    * @see \Drupal\block\BlockBase::blockSubmit()
@@ -564,4 +575,46 @@ public function submit($form, &$form_state) {
    */
   public function blockSubmit($form, &$form_state) {}
 
+  /**
+   * Implements \Drupal\block\BlockInterface::build().
+   *
+   * Allows blocks to be altered after they are built.
+   *
+   * Most block plugins should not override this method. To define how a
+   * particular block is rendered, implement the abstract method
+   * BlockBase::blockBuild().
+   *
+   * @return array $build
+   *   A renderable array of data.
+   *   - #title: The default localized title of the block.
+   *
+   * @todo Add specific examples of $id and $name below.
+   *
+   * @see \Drupal\block\BlockBase::blockBuild()
+   */
+  public function build() {
+    // Allow modules to modify the block before it is viewed, via either
+    // hook_block_view_alter(), hook_block_view_ID_alter(), or
+    // hook_block_view_NAME_alter().
+    $id = str_replace(':', '__', $this->getPluginId());
+
+    $config = $this->getConfig();
+    $config_id = explode('.', $config['config_id']);
+    $name = array_pop($config_id);
+
+    $build = $this->blockBuild();
+    drupal_alter(array('block_view', "block_view_$id", "block_view_$name"), $build, $this);
+    return $build;
+  }
+
+  /**
+   * Builds the renderable array for a specific block type.
+   *
+   * @return array
+   *   A renderable array representing the output of the block.
+   *
+   * @see \Drupal\block\BlockBase::build()
+   */
+  abstract public function blockBuild();
+
 }
diff --git a/core/modules/block/tests/lib/Drupal/block_test/Plugin/block/block/TestCacheBlock.php b/core/modules/block/tests/lib/Drupal/block_test/Plugin/block/block/TestCacheBlock.php
index 57a7ac8..aeb7709 100644
--- a/core/modules/block/tests/lib/Drupal/block_test/Plugin/block/block/TestCacheBlock.php
+++ b/core/modules/block/tests/lib/Drupal/block_test/Plugin/block/block/TestCacheBlock.php
@@ -34,9 +34,9 @@ public function blockSettings() {
   }
 
   /**
-   * Implements \Drupal\block\BlockInterface::build().
+   * Implements \Drupal\block\BlockBase::blockBuild().
    */
-  public function build() {
+  public function blockBuild() {
     return array(
       '#children' => state()->get('block_test.content'),
     );
diff --git a/core/modules/book/lib/Drupal/book/Plugin/block/block/BookNavigationBlock.php b/core/modules/book/lib/Drupal/book/Plugin/block/block/BookNavigationBlock.php
index edaae57..c1823e1 100644
--- a/core/modules/book/lib/Drupal/book/Plugin/block/block/BookNavigationBlock.php
+++ b/core/modules/book/lib/Drupal/book/Plugin/block/block/BookNavigationBlock.php
@@ -59,9 +59,9 @@ public function blockSubmit($form, &$form_state) {
   }
 
   /**
-   * Implements \Drupal\block\BlockInterface::build().
+   * Implements \Drupal\block\BlockBase::blockBuild().
    */
-  public function build() {
+  public function blockBuild() {
     $current_bid = 0;
     if ($node = menu_get_object()) {
       $current_bid = empty($node->book['bid']) ? 0 : $node->book['bid'];
diff --git a/core/modules/comment/lib/Drupal/comment/Plugin/block/block/RecentCommentsBlock.php b/core/modules/comment/lib/Drupal/comment/Plugin/block/block/RecentCommentsBlock.php
index e9ce19b..d5c3d7b 100644
--- a/core/modules/comment/lib/Drupal/comment/Plugin/block/block/RecentCommentsBlock.php
+++ b/core/modules/comment/lib/Drupal/comment/Plugin/block/block/RecentCommentsBlock.php
@@ -59,9 +59,9 @@ public function blockSubmit($form, &$form_state) {
   }
 
   /**
-   * Implements \Drupal\block\BlockInterface::build();
+   * Implements \Drupal\block\BlockBase::blockBuild().
    */
-  public function build() {
+  public function blockBuild() {
     return array(
       '#theme' => 'comment_block',
       '#number' => $this->configuration['block_count'],
diff --git a/core/modules/forum/lib/Drupal/forum/Plugin/block/block/ActiveTopicsBlock.php b/core/modules/forum/lib/Drupal/forum/Plugin/block/block/ActiveTopicsBlock.php
index 9b8cda5..afa7117 100644
--- a/core/modules/forum/lib/Drupal/forum/Plugin/block/block/ActiveTopicsBlock.php
+++ b/core/modules/forum/lib/Drupal/forum/Plugin/block/block/ActiveTopicsBlock.php
@@ -22,9 +22,9 @@
 class ActiveTopicsBlock extends ForumBlockBase {
 
   /**
-   * Implements \Drupal\block\BlockInterface::build().
+   * Implements \Drupal\block\BlockBase::blockBuild().
    */
-  public function build() {
+  public function blockBuild() {
     $query = db_select('forum_index', 'f')
       ->fields('f')
       ->addTag('node_access')
diff --git a/core/modules/forum/lib/Drupal/forum/Plugin/block/block/NewTopicsBlock.php b/core/modules/forum/lib/Drupal/forum/Plugin/block/block/NewTopicsBlock.php
index 1b5d9b4..083469c 100644
--- a/core/modules/forum/lib/Drupal/forum/Plugin/block/block/NewTopicsBlock.php
+++ b/core/modules/forum/lib/Drupal/forum/Plugin/block/block/NewTopicsBlock.php
@@ -22,9 +22,9 @@
 class NewTopicsBlock extends ForumBlockBase {
 
   /**
-   * Implements \Drupal\block\BlockInterface::build().
+   * Implements \Drupal\block\BlockBase::blockBuild().
    */
-  public function build() {
+  public function blockBuild() {
     $query = db_select('forum_index', 'f')
       ->fields('f')
       ->addTag('node_access')
diff --git a/core/modules/language/lib/Drupal/language/Plugin/block/block/LanguageBlock.php b/core/modules/language/lib/Drupal/language/Plugin/block/block/LanguageBlock.php
index f303211..74fb83a 100644
--- a/core/modules/language/lib/Drupal/language/Plugin/block/block/LanguageBlock.php
+++ b/core/modules/language/lib/Drupal/language/Plugin/block/block/LanguageBlock.php
@@ -31,9 +31,9 @@ function blockAccess() {
   }
 
   /**
-   * Implements \Drupal\block\BlockInterface::build().
+   * Implements \Drupal\block\BlockBase::blockBuild().
    */
-  function build() {
+  public function blockBuild() {
     $path = drupal_is_front_page() ? '<front>' : current_path();
     list($plugin_id, $type) = explode(':', $this->getPluginId());
     $links = language_negotiation_get_switch_links($type, $path);
diff --git a/core/modules/menu/lib/Drupal/menu/Plugin/block/block/MenuBlock.php b/core/modules/menu/lib/Drupal/menu/Plugin/block/block/MenuBlock.php
index cff3abd..7134dc50 100644
--- a/core/modules/menu/lib/Drupal/menu/Plugin/block/block/MenuBlock.php
+++ b/core/modules/menu/lib/Drupal/menu/Plugin/block/block/MenuBlock.php
@@ -24,9 +24,9 @@
 class MenuBlock extends SystemMenuBlock {
 
   /**
-   * Overrides \Drupal\system\Plugin\block\block\SystemMenuBlock::build().
+   * Implements \Drupal\block\BlockBase::blockBuild().
    */
-  public function build() {
+  public function blockBuild() {
     list($plugin, $menu) = explode(':', $this->getPluginId());
     return menu_tree($menu);
   }
diff --git a/core/modules/node/lib/Drupal/node/Plugin/block/block/RecentContentBlock.php b/core/modules/node/lib/Drupal/node/Plugin/block/block/RecentContentBlock.php
index f7003b4..cb05c5c 100644
--- a/core/modules/node/lib/Drupal/node/Plugin/block/block/RecentContentBlock.php
+++ b/core/modules/node/lib/Drupal/node/Plugin/block/block/RecentContentBlock.php
@@ -59,9 +59,9 @@ public function blockSubmit($form, &$form_state) {
   }
 
   /**
-   * Implements \Drupal\block\BlockInterface::build().
+   * Implements \Drupal\block\BlockBase::blockBuild().
    */
-  public function build() {
+  public function blockBuild() {
     if ($nodes = node_get_recent($this->configuration['block_count'])) {
       return array(
         '#theme' => 'node_recent_block',
diff --git a/core/modules/node/lib/Drupal/node/Plugin/block/block/SyndicateBlock.php b/core/modules/node/lib/Drupal/node/Plugin/block/block/SyndicateBlock.php
index 460045a..5c83e27 100644
--- a/core/modules/node/lib/Drupal/node/Plugin/block/block/SyndicateBlock.php
+++ b/core/modules/node/lib/Drupal/node/Plugin/block/block/SyndicateBlock.php
@@ -39,9 +39,9 @@ public function blockAccess() {
   }
 
   /**
-   * Implements \Drupal\block\BlockInterface::build();
+   * Implements \Drupal\block\BlockBase::blockBuild().
    */
-  public function build() {
+  public function blockBuild() {
     return array(
       '#theme' => 'feed_icon',
       '#url' => 'rss.xml',
diff --git a/core/modules/poll/lib/Drupal/poll/Plugin/block/block/PollRecentBlock.php b/core/modules/poll/lib/Drupal/poll/Plugin/block/block/PollRecentBlock.php
index 67c13ab..b597741 100644
--- a/core/modules/poll/lib/Drupal/poll/Plugin/block/block/PollRecentBlock.php
+++ b/core/modules/poll/lib/Drupal/poll/Plugin/block/block/PollRecentBlock.php
@@ -65,9 +65,9 @@ public function blockAccess() {
   }
 
   /**
-   * Implements \Drupal\block\BlockInterface::build().
+   * Implements \Drupal\block\BlockBase::blockBuild().
    */
-  public function build() {
+  public function blockBuild() {
     $poll = node_load($this->record);
     if ($poll->nid) {
       $poll = poll_block_latest_poll_view($poll);
diff --git a/core/modules/search/lib/Drupal/search/Plugin/block/block/SearchBlock.php b/core/modules/search/lib/Drupal/search/Plugin/block/block/SearchBlock.php
index a6fbb04..d9bdb7c 100644
--- a/core/modules/search/lib/Drupal/search/Plugin/block/block/SearchBlock.php
+++ b/core/modules/search/lib/Drupal/search/Plugin/block/block/SearchBlock.php
@@ -30,9 +30,9 @@ public function blockAccess() {
   }
 
   /**
-   * Implements \Drupal\block\BlockInterface::build().
+   * Implements \Drupal\block\BlockBase::blockBuild().
    */
-  public function build() {
+  public function blockBuild() {
     return array(drupal_get_form('search_block_form'));
   }
 
diff --git a/core/modules/shortcut/lib/Drupal/shortcut/Plugin/block/block/ShortcutsBlock.php b/core/modules/shortcut/lib/Drupal/shortcut/Plugin/block/block/ShortcutsBlock.php
index 7638a29..d236a19 100644
--- a/core/modules/shortcut/lib/Drupal/shortcut/Plugin/block/block/ShortcutsBlock.php
+++ b/core/modules/shortcut/lib/Drupal/shortcut/Plugin/block/block/ShortcutsBlock.php
@@ -23,9 +23,9 @@
 class ShortcutsBlock extends BlockBase {
 
   /**
-   * Implements \Drupal\block\BlockInterface::build().
+   * Implements \Drupal\block\BlockBase::blockBuild().
    */
-  public function build() {
+  public function blockBuild() {
     return array(
       shortcut_renderable_links(shortcut_current_displayed_set()),
     );
diff --git a/core/modules/statistics/lib/Drupal/statistics/Plugin/block/block/StatisticsPopularBlock.php b/core/modules/statistics/lib/Drupal/statistics/Plugin/block/block/StatisticsPopularBlock.php
index cb82dcc..8c9fdf6 100644
--- a/core/modules/statistics/lib/Drupal/statistics/Plugin/block/block/StatisticsPopularBlock.php
+++ b/core/modules/statistics/lib/Drupal/statistics/Plugin/block/block/StatisticsPopularBlock.php
@@ -116,9 +116,9 @@ public function blockSubmit($form, &$form_state) {
   }
 
   /**
-   * Implements \Drupal\block\BlockInterface::build().
+   * Implements \Drupal\block\BlockBase::blockBuild().
    */
-  public function build() {
+  public function blockBuild() {
     $content = array();
 
     if ($this->day_list) {
diff --git a/core/modules/system/lib/Drupal/system/Plugin/block/block/SystemHelpBlock.php b/core/modules/system/lib/Drupal/system/Plugin/block/block/SystemHelpBlock.php
index ac50042..6026f83 100644
--- a/core/modules/system/lib/Drupal/system/Plugin/block/block/SystemHelpBlock.php
+++ b/core/modules/system/lib/Drupal/system/Plugin/block/block/SystemHelpBlock.php
@@ -38,9 +38,9 @@ public function blockAccess() {
   }
 
   /**
-   * Implements \Drupal\block\BlockInterface::build().
+   * Implements \Drupal\block\BlockBase::blockBuild().
    */
-  public function build() {
+  public function blockBuild() {
     return array(
       '#children' => $this->help,
     );
diff --git a/core/modules/system/lib/Drupal/system/Plugin/block/block/SystemMainBlock.php b/core/modules/system/lib/Drupal/system/Plugin/block/block/SystemMainBlock.php
index 21e4268..8b40092 100644
--- a/core/modules/system/lib/Drupal/system/Plugin/block/block/SystemMainBlock.php
+++ b/core/modules/system/lib/Drupal/system/Plugin/block/block/SystemMainBlock.php
@@ -23,9 +23,9 @@
 class SystemMainBlock extends BlockBase {
 
   /**
-   * Implements \Drupal\block\BlockInterface::build().
+   * Implements \Drupal\block\BlockBase::blockBuild().
    */
-  public function build() {
+  public function blockBuild() {
     return array(
       drupal_set_page_content()
     );
diff --git a/core/modules/system/lib/Drupal/system/Plugin/block/block/SystemMenuBlock.php b/core/modules/system/lib/Drupal/system/Plugin/block/block/SystemMenuBlock.php
index 6d3b837..0307257 100644
--- a/core/modules/system/lib/Drupal/system/Plugin/block/block/SystemMenuBlock.php
+++ b/core/modules/system/lib/Drupal/system/Plugin/block/block/SystemMenuBlock.php
@@ -33,9 +33,9 @@ public function blockAccess() {
   }
 
   /**
-   * Implements \Drupal\block\BlockInterface::build().
+   * Implements \Drupal\block\BlockBase::blockBuild().
    */
-  public function build() {
+  public function blockBuild() {
     list($plugin, $derivative) = explode(':', $this->getPluginId());
     // Derivatives are prefixed with 'menu-'.
     $menu = substr($derivative, 5);
diff --git a/core/modules/system/lib/Drupal/system/Plugin/block/block/SystemPoweredByBlock.php b/core/modules/system/lib/Drupal/system/Plugin/block/block/SystemPoweredByBlock.php
index 4b94df0..b363725 100644
--- a/core/modules/system/lib/Drupal/system/Plugin/block/block/SystemPoweredByBlock.php
+++ b/core/modules/system/lib/Drupal/system/Plugin/block/block/SystemPoweredByBlock.php
@@ -23,9 +23,9 @@
 class SystemPoweredByBlock extends BlockBase {
 
   /**
-   * Implements \Drupal\block\BlockInterface::build().
+   * Implements \Drupal\block\BlockBase::blockBuild().
    */
-  public function build() {
+  public function blockBuild() {
     return array(
       '#children' => theme('system_powered_by'),
     );
diff --git a/core/modules/user/lib/Drupal/user/Plugin/block/block/UserLoginBlock.php b/core/modules/user/lib/Drupal/user/Plugin/block/block/UserLoginBlock.php
index 4ca502c..51bc8ee 100644
--- a/core/modules/user/lib/Drupal/user/Plugin/block/block/UserLoginBlock.php
+++ b/core/modules/user/lib/Drupal/user/Plugin/block/block/UserLoginBlock.php
@@ -30,9 +30,9 @@ public function blockAccess() {
   }
 
   /**
-   * Implements \Drupal\block\BlockInterface::build().
+   * Implements \Drupal\block\BlockBase::blockBuild().
    */
-  public function build() {
+  public function blockBuild() {
     $form = drupal_get_form('user_login_form');
     unset($form['name']['#attributes']['autofocus']);
     unset($form['name']['#description']);
diff --git a/core/modules/user/lib/Drupal/user/Plugin/block/block/UserNewBlock.php b/core/modules/user/lib/Drupal/user/Plugin/block/block/UserNewBlock.php
index 742cd89..7f97df6 100644
--- a/core/modules/user/lib/Drupal/user/Plugin/block/block/UserNewBlock.php
+++ b/core/modules/user/lib/Drupal/user/Plugin/block/block/UserNewBlock.php
@@ -62,9 +62,9 @@ public function blockSubmit($form, &$form_state) {
   }
 
   /**
-   * Implements \Drupal\block\BlockInterface::build().
+   * Implements \Drupal\block\BlockBase::blockBuild().
    */
-  public function build() {
+  public function blockBuild() {
     // Retrieve a list of new users who have accessed the site successfully.
     $items = db_query_range('SELECT uid, name FROM {users} WHERE status <> 0 AND access <> 0 ORDER BY created DESC', 0, $this->configuration['whois_new_count'])->fetchAll();
     $build = array(
diff --git a/core/modules/user/lib/Drupal/user/Plugin/block/block/UserOnlineBlock.php b/core/modules/user/lib/Drupal/user/Plugin/block/block/UserOnlineBlock.php
index 017a56f..b0caf90 100644
--- a/core/modules/user/lib/Drupal/user/Plugin/block/block/UserOnlineBlock.php
+++ b/core/modules/user/lib/Drupal/user/Plugin/block/block/UserOnlineBlock.php
@@ -76,9 +76,9 @@ public function blockSubmit($form, &$form_state) {
   }
 
   /**
-   * Implements \Drupal\block\BlockInterface::build().
+   * Implements \Drupal\block\BlockBase::blockBuild().
    */
-  public function build() {
+  public function blockBuild() {
     // Count users active within the defined period.
     $interval = REQUEST_TIME - $this->configuration['seconds_online'];
 
diff --git a/core/modules/views/lib/Drupal/views/Plugin/block/block/ViewsBlock.php b/core/modules/views/lib/Drupal/views/Plugin/block/block/ViewsBlock.php
index 4131651..296212c 100644
--- a/core/modules/views/lib/Drupal/views/Plugin/block/block/ViewsBlock.php
+++ b/core/modules/views/lib/Drupal/views/Plugin/block/block/ViewsBlock.php
@@ -69,9 +69,9 @@ public function blockForm($form, &$form_state) {
   }
 
   /**
-   * Implements \Drupal\block\BlockInterface::build().
+   * Implements \Drupal\block\BlockBase::blockBuild().
    */
-  public function build() {
+  public function blockBuild() {
     $output = $this->view->executeDisplay($this->displayID);
     // Set the subject to the title configured in the view.
     $this->configuration['subject'] = filter_xss_admin($this->view->getTitle());
diff --git a/core/modules/views/lib/Drupal/views/Plugin/block/block/ViewsExposedFilterBlock.php b/core/modules/views/lib/Drupal/views/Plugin/block/block/ViewsExposedFilterBlock.php
index f274913..2d51c25 100644
--- a/core/modules/views/lib/Drupal/views/Plugin/block/block/ViewsExposedFilterBlock.php
+++ b/core/modules/views/lib/Drupal/views/Plugin/block/block/ViewsExposedFilterBlock.php
@@ -23,9 +23,9 @@
 class ViewsExposedFilterBlock extends ViewsBlock {
 
   /**
-   * Overrides \Drupal\views\Plugin\block\block\ViewsBlock::build().
+   * Implements \Drupal\block\BlockBase::blockBuild().
    */
-  public function build() {
+  public function blockBuild() {
     $type = 'exp';
     $output = $this->view->display_handler->viewSpecialBlocks($type);
     // Before returning the block output, convert it to a renderable array with