diff --git a/core/lib/Drupal/Core/Plugin/DefaultPluginBag.php b/core/lib/Drupal/Core/Plugin/DefaultPluginBag.php
index 9fabf75..2d301f5 100644
--- a/core/lib/Drupal/Core/Plugin/DefaultPluginBag.php
+++ b/core/lib/Drupal/Core/Plugin/DefaultPluginBag.php
@@ -76,4 +76,64 @@ protected function initializePlugin($instance_id) {
     }
   }
 
+  /**
+   * Sorts all plugin instances in this bag.
+   *
+   * @return self
+   *   Returns the plugin bag.
+   */
+  public function sort() {
+    uasort($this->instanceIDs, array($this, 'sortHelper'));
+    return $this;
+  }
+
+  /**
+   * Provides uasort() callback to sort plugins.
+   */
+  public function sortHelper($aID, $bID) {
+    $a = $this->get($aID);
+    $b = $this->get($bID);
+    return strnatcasecmp($a->getPluginId(), $b->getPluginId());
+  }
+
+  /**
+   * Returns the current configuration of all plugins in this bag.
+   *
+   * @return array
+   *   An associative array keyed by instance ID, whose values are up-to-date
+   *   plugin configurations.
+   */
+  public function getConfiguration() {
+    $instances = array();
+    $this->rewind();
+    foreach ($this as $instance_id => $instance) {
+      if ($instance instanceof ConfigurablePluginInterface) {
+        $instances[$instance_id] = $instance->getConfiguration();
+      }
+      else {
+        $instances[$instance_id] = $this->configurations[$instance_id];
+      }
+    }
+    return $instances;
+  }
+
+  /**
+   * Updates the configuration for a plugin instance.
+   *
+   * If there is no plugin instance yet, a new will be instantiated. Otherwise,
+   * the existing instance is updated with the new configuration.
+   *
+   * @param string $instance_id
+   *   The ID of a plugin to set the configuration for.
+   * @param array $configuration
+   *   The plugin configuration to set.
+   */
+  public function setConfiguration($instance_id, array $configuration) {
+    $this->configurations[$instance_id] = $configuration;
+    $instance = $this->get($instance_id);
+    if ($instance instanceof ConfigurablePluginInterface) {
+      $instance->setConfiguration($configuration);
+    }
+  }
+
 }
diff --git a/core/modules/block/lib/Drupal/block/BlockBase.php b/core/modules/block/lib/Drupal/block/BlockBase.php
index cee4707..947439e 100644
--- a/core/modules/block/lib/Drupal/block/BlockBase.php
+++ b/core/modules/block/lib/Drupal/block/BlockBase.php
@@ -64,34 +64,14 @@ public function setConfiguration(array $configuration) {
   }
 
   /**
-   * Sets a particular value in the block settings.
-   *
-   * @param string $key
-   *   The key of PluginBase::$configuration to set.
-   * @param mixed $value
-   *   The value to set for the provided key.
-   *
-   * @todo This doesn't belong here. Move this into a new base class in
-   *   http://drupal.org/node/1764380.
-   * @todo This does not set a value in config(), so the name is confusing.
-   *
-   * @see \Drupal\Component\Plugin\PluginBase::$configuration
+   * {@inheritdoc}
    */
   public function setConfig($key, $value) {
     $this->configuration[$key] = $value;
   }
 
   /**
-   * Indicates whether block-specific criteria allow access to the block.
-   *
-   * Blocks with access restrictions that should always be applied,
-   * regardless of user-configured settings, should implement this method
-   * with that access control logic.
-   *
-   * @return bool
-   *   FALSE to deny access to the block, or TRUE to allow access.
-   *
-   * @see hook_block_access()
+   * {@inheritdoc}
    */
   public function access() {
     // By default, the block is visible unless user-configured rules indicate
@@ -136,20 +116,7 @@ public function buildConfigurationForm(array $form, array &$form_state) {
   }
 
   /**
-   * Returns the configuration form elements specific to this block plugin.
-   *
-   * Blocks that need to add form elements to the normal block configuration
-   * form should implement this method.
-   *
-   * @param array $form
-   *   The form definition array for the block configuration form.
-   * @param array $form_state
-   *   An array containing the current state of the configuration form.
-   *
-   * @return array $form
-   *   The renderable form array representing the entire configuration form.
-   *
-   * @see \Drupal\block\BlockBase::buildConfigurationForm()
+   * {@inheritdoc}
    */
   public function blockForm($form, &$form_state) {
     return array();
@@ -170,20 +137,7 @@ public function validateConfigurationForm(array &$form, array &$form_state) {
   }
 
   /**
-   * Adds block type-specific validation for the block form.
-   *
-   * Note that this method takes the form structure and form state arrays for
-   * the full block configuration form as arguments, not just the elements
-   * defined in BlockBase::blockForm().
-   *
-   * @param array $form
-   *   The form definition array for the full block configuration form.
-   * @param array $form_state
-   *   An array containing the current state of the configuration form.
-   *
-   * @see \Drupal\block\BlockBase::blockForm()
-   * @see \Drupal\block\BlockBase::blockSubmit()
-   * @see \Drupal\block\BlockBase::validateConfigurationForm()
+   * {@inheritdoc}
    */
   public function blockValidate($form, &$form_state) {}
 
@@ -207,20 +161,8 @@ public function submitConfigurationForm(array &$form, array &$form_state) {
   }
 
   /**
-   * Adds block type-specific submission handling for the block form.
-   *
-   * Note that this method takes the form structure and form state arrays for
-   * the full block configuration form as arguments, not just the elements
-   * defined in BlockBase::blockForm().
-   *
-   * @param array $form
-   *   The form definition array for the full block configuration form.
-   * @param array $form_state
-   *   An array containing the current state of the configuration form.
-   *
-   * @see \Drupal\block\BlockBase::blockForm()
-   * @see \Drupal\block\BlockBase::blockValidate()
-   * @see \Drupal\block\BlockBase::submitConfigurationForm()
+   * {@inheritdoc}
    */
   public function blockSubmit($form, &$form_state) {}
+
 }
diff --git a/core/modules/block/lib/Drupal/block/BlockPluginInterface.php b/core/modules/block/lib/Drupal/block/BlockPluginInterface.php
index b960090..a5c4f52 100644
--- a/core/modules/block/lib/Drupal/block/BlockPluginInterface.php
+++ b/core/modules/block/lib/Drupal/block/BlockPluginInterface.php
@@ -18,8 +18,6 @@
  *   architecture and the relationships between the various objects, including
  *   brif references to the important components that are not coupled to the
  *   interface.
- *
- * @see \Drupal\block\BlockBase
  */
 interface BlockPluginInterface extends ConfigurablePluginInterface, PluginFormInterface, PluginInspectionInterface {
 
@@ -58,4 +56,70 @@ public function access();
    */
   public function build();
 
+  /**
+   * Sets a particular value in the block settings.
+   *
+   * @param string $key
+   *   The key of PluginBase::$configuration to set.
+   * @param mixed $value
+   *   The value to set for the provided key.
+   *
+   * @todo This doesn't belong here. Move this into a new base class in
+   *   http://drupal.org/node/1764380.
+   * @todo This does not set a value in config(), so the name is confusing.
+   *
+   * @see \Drupal\Component\Plugin\PluginBase::$configuration
+   */
+  public function setConfig($key, $value);
+
+  /**
+   * Returns the configuration form elements specific to this block plugin.
+   *
+   * Blocks that need to add form elements to the normal block configuration
+   * form should implement this method.
+   *
+   * @param array $form
+   *   The form definition array for the block configuration form.
+   * @param array $form_state
+   *   An array containing the current state of the configuration form.
+   *
+   * @return array $form
+   *   The renderable form array representing the entire configuration form.
+   */
+  public function blockForm($form, &$form_state);
+
+  /**
+   * Adds block type-specific validation for the block form.
+   *
+   * Note that this method takes the form structure and form state arrays for
+   * the full block configuration form as arguments, not just the elements
+   * defined in BlockPluginInterface::blockForm().
+   *
+   * @param array $form
+   *   The form definition array for the full block configuration form.
+   * @param array $form_state
+   *   An array containing the current state of the configuration form.
+   *
+   * @see \Drupal\block\BlockPluginInterface::blockForm()
+   * @see \Drupal\block\BlockPluginInterface::blockSubmit()
+   */
+  public function blockValidate($form, &$form_state);
+
+  /**
+   * Adds block type-specific submission handling for the block form.
+   *
+   * Note that this method takes the form structure and form state arrays for
+   * the full block configuration form as arguments, not just the elements
+   * defined in BlockPluginInterface::blockForm().
+   *
+   * @param array $form
+   *   The form definition array for the full block configuration form.
+   * @param array $form_state
+   *   An array containing the current state of the configuration form.
+   *
+   * @see \Drupal\block\BlockPluginInterface::blockForm()
+   * @see \Drupal\block\BlockPluginInterface::blockValidate()
+   */
+  public function blockSubmit($form, &$form_state);
+
 }
diff --git a/core/modules/filter/lib/Drupal/filter/FilterBag.php b/core/modules/filter/lib/Drupal/filter/FilterBag.php
index fcb8aa9..3e7cec6 100644
--- a/core/modules/filter/lib/Drupal/filter/FilterBag.php
+++ b/core/modules/filter/lib/Drupal/filter/FilterBag.php
@@ -56,22 +56,6 @@ public function getAll() {
   }
 
   /**
-   * Updates the configuration for a filter plugin instance.
-   *
-   * If there is no plugin instance yet, a new will be instantiated. Otherwise,
-   * the existing instance is updated with the new configuration.
-   *
-   * @param string $instance_id
-   *   The ID of a filter plugin to set the configuration for.
-   * @param array $configuration
-   *   The filter plugin configuration to set.
-   */
-  public function setConfig($instance_id, array $configuration) {
-    $this->configurations[$instance_id] = $configuration;
-    $this->get($instance_id)->setConfiguration($configuration);
-  }
-
-  /**
    * {@inheritdoc}
    */
   protected function initializePlugin($instance_id) {
@@ -104,20 +88,15 @@ protected function initializePlugin($instance_id) {
   }
 
   /**
-   * Sorts all filter plugin instances in this bag.
-   *
-   * @return \Drupal\filter\FilterBag
+   * {@inheritdoc}
    */
   public function sort() {
     $this->getAll();
-    uasort($this->instanceIDs, array($this, 'sortHelper'));
-    return $this;
+    return parent::sort();
   }
 
   /**
-   * uasort() callback to sort filters by status, weight, module, and name.
-   *
-   * @see \Drupal\filter\FilterFormatStorageController::preSave()
+   * {@inheritdoc}
    */
   public function sortHelper($aID, $bID) {
     $a = $this->get($aID);
@@ -134,22 +113,4 @@ public function sortHelper($aID, $bID) {
     return strnatcasecmp($a->getPluginId(), $b->getPluginId());
   }
 
-  /**
-   * Returns the current configuration of all filters in this bag.
-   *
-   * @return array
-   *   An associative array keyed by filter plugin instance ID, whose values
-   *   are filter configurations.
-   *
-   * @see \Drupal\filter\Plugin\Filter\FilterInterface::getConfiguration()
-   */
-  public function getConfiguration() {
-    $filters = array();
-    $this->rewind();
-    foreach ($this as $instance_id => $instance) {
-      $filters[$instance_id] = $instance->getConfiguration();
-    }
-    return $filters;
-  }
-
 }
diff --git a/core/modules/filter/lib/Drupal/filter/Plugin/Core/Entity/FilterFormat.php b/core/modules/filter/lib/Drupal/filter/Plugin/Core/Entity/FilterFormat.php
index 87d7447..7541b53 100644
--- a/core/modules/filter/lib/Drupal/filter/Plugin/Core/Entity/FilterFormat.php
+++ b/core/modules/filter/lib/Drupal/filter/Plugin/Core/Entity/FilterFormat.php
@@ -155,7 +155,7 @@ public function filters($instance_id = NULL) {
   public function setFilterConfig($instance_id, array $configuration) {
     $this->filters[$instance_id] = $configuration;
     if (isset($this->filterBag)) {
-      $this->filterBag->setConfig($instance_id, $configuration);
+      $this->filterBag->setConfiguration($instance_id, $configuration);
     }
     return $this;
   }
diff --git a/core/modules/image/lib/Drupal/image/ImageEffectBag.php b/core/modules/image/lib/Drupal/image/ImageEffectBag.php
index 437d8bb..11f173b 100644
--- a/core/modules/image/lib/Drupal/image/ImageEffectBag.php
+++ b/core/modules/image/lib/Drupal/image/ImageEffectBag.php
@@ -22,22 +22,6 @@ class ImageEffectBag extends DefaultPluginBag {
   protected $pluginKey = 'id';
 
   /**
-   * Returns the current configuration of all image effects in this bag.
-   *
-   * @return array
-   *   An associative array keyed by image effect UUID, whose values are image
-   *   effect configurations.
-   */
-  public function getConfiguration() {
-    $instances = array();
-    $this->rewind();
-    foreach ($this as $instance_id => $instance) {
-      $instances[$instance_id] = $instance->getConfiguration();
-    }
-    return $instances;
-  }
-
-  /**
    * Removes an instance ID.
    *
    * @param string $instance_id
@@ -58,24 +42,22 @@ public function removeInstanceID($instance_id) {
    *   The image effect configuration to set.
    *
    * @return string
+   *   The image effect UUID.
    */
-  public function setConfig(array $configuration) {
+  public function updateConfiguration(array $configuration) {
     // Derive the instance ID from the configuration.
     if (empty($configuration['uuid'])) {
       $uuid_generator = new Uuid();
       $configuration['uuid'] = $uuid_generator->generate();
     }
     $instance_id = $configuration['uuid'];
-    $this->configurations[$instance_id] = $configuration;
-    $this->get($instance_id)->setConfiguration($configuration);
+    $this->setConfiguration($instance_id, $configuration);
     $this->addInstanceID($instance_id);
     return $instance_id;
   }
 
   /**
-   * Sorts all image effect instances in this bag.
-   *
-   * @return self
+   * {@inheritdoc}
    */
   public function sort() {
     uasort($this->configurations, 'drupal_sort_weight');
diff --git a/core/modules/image/lib/Drupal/image/Plugin/Core/Entity/ImageStyle.php b/core/modules/image/lib/Drupal/image/Plugin/Core/Entity/ImageStyle.php
index 8f9e5bd..2b1afbf 100644
--- a/core/modules/image/lib/Drupal/image/Plugin/Core/Entity/ImageStyle.php
+++ b/core/modules/image/lib/Drupal/image/Plugin/Core/Entity/ImageStyle.php
@@ -352,7 +352,7 @@ public function getEffects() {
    * {@inheritdoc}
    */
   public function saveImageEffect(array $configuration) {
-    $effect_id = $this->getEffects()->setConfig($configuration);
+    $effect_id = $this->getEffects()->updateConfiguration($configuration);
     $this->save();
     return $effect_id;
   }
diff --git a/core/modules/views/lib/Drupal/views/Plugin/views/display/DisplayPluginBase.php b/core/modules/views/lib/Drupal/views/Plugin/views/display/DisplayPluginBase.php
index b0cbb7b..3957677 100644
--- a/core/modules/views/lib/Drupal/views/Plugin/views/display/DisplayPluginBase.php
+++ b/core/modules/views/lib/Drupal/views/Plugin/views/display/DisplayPluginBase.php
@@ -99,6 +99,21 @@
    */
   protected $usesAreas = TRUE;
 
+  /**
+   * Constructs a new DisplayPluginBase object.
+   *
+   * Because DisplayPluginBase::initDisplay() takes the display configuration by
+   * reference and handles it differently than usual plugin configuration, pass
+   * an empty array of configuration to the parent. This prevents our
+   * configuration from being duplicated.
+   *
+   * @todo Replace DisplayPluginBase::$display with
+   *   DisplayPluginBase::$configuration to standardize with other plugins.
+   */
+  public function __construct(array $configuration, $plugin_id, array $plugin_definition) {
+    parent::__construct(array(), $plugin_id, $plugin_definition);
+  }
+
   public function initDisplay(ViewExecutable $view, array &$display, array &$options = NULL) {
     $this->setOptionDefaults($this->options, $this->defineOptions());
     $this->view = $view;