diff --git a/src/Plugin/DisplayVariant/BlockDisplayVariant.php b/src/Plugin/DisplayVariant/BlockDisplayVariant.php
index 238aa46..87ce680 100644
--- a/src/Plugin/DisplayVariant/BlockDisplayVariant.php
+++ b/src/Plugin/DisplayVariant/BlockDisplayVariant.php
@@ -68,6 +68,15 @@
   protected $token;
 
   /**
+   * An array of collected contexts.
+   *
+   * This is only used on runtime, and is not stored.
+   *
+   * @var \Drupal\Component\Plugin\Context\ContextInterface[]
+   */
+  protected $contexts = [];
+
+  /**
    * Constructs a new BlockDisplayVariant.
    *
    * @param array $configuration
@@ -112,26 +121,6 @@ public static function create(ContainerInterface $container, array $configuratio
   /**
    * {@inheritdoc}
    */
-  public function build() {
-    // Set default page cache keys that include the display.
-    $build['#cache']['keys'] = [
-      'ctools_block_display',
-      // The UUID of this display.
-      // @todo should have an API for this?
-      $this->configuration['uuid'],
-    ];
-    $build['#pre_render'][] = [$this, 'buildRegions'];
-    return $build;
-  }
-
-  /**
-   * #pre_render callback for building the regions.
-   */
-  abstract public function buildRegions(array $build);
-
-  /**
-   * {@inheritdoc}
-   */
   public function access(AccountInterface $account = NULL) {
     // Delegate to the conditions.
     return $this->determineSelectionAccess($this->getContexts());
@@ -180,6 +169,29 @@ public function getSelectionLogic() {
   }
 
   /**
+   * Gets the contexts.
+   *
+   * @return \Drupal\Component\Plugin\Context\ContextInterface[]
+   *   An array of set contexts, keyed by context name.
+   */
+  public function getContexts() {
+    return $this->contexts;
+  }
+
+  /**
+   * Sets the contexts.
+   *
+   * @param \Drupal\Component\Plugin\Context\ContextInterface[] $contexts
+   *   An array of contexts, keyed by context name.
+   *
+   * @return $this
+   */
+  public function setContexts(array $contexts) {
+    $this->contexts = $contexts;
+    return $this;
+  }
+
+  /**
    * {@inheritdoc}
    */
   protected function contextHandler() {
diff --git a/tests/src/Unit/BlockDisplayVariantTest.php b/tests/src/Unit/BlockDisplayVariantTest.php
index b2dd2d7..282b116 100644
--- a/tests/src/Unit/BlockDisplayVariantTest.php
+++ b/tests/src/Unit/BlockDisplayVariantTest.php
@@ -8,18 +8,12 @@
 namespace Drupal\Tests\ctools\Unit;
 
 use Drupal\Component\Uuid\UuidInterface;
-use Drupal\Core\Access\AccessResult;
-use Drupal\Core\Block\BlockPluginInterface;
-use Drupal\Core\Cache\Context\CacheContextsManager;
 use Drupal\Core\Plugin\Context\ContextHandlerInterface;
-use Drupal\Core\Plugin\ContextAwarePluginInterface;
 use Drupal\Core\Form\FormState;
 use Drupal\Core\Session\AccountInterface;
 use Drupal\Core\Utility\Token;
-use Drupal\ctools\Plugin\BlockPluginCollection;
 use Drupal\ctools\Plugin\DisplayVariant\BlockDisplayVariant;
 use Drupal\Tests\UnitTestCase;
-use Symfony\Component\DependencyInjection\ContainerBuilder;
 
 /**
  * Tests the block display variant plugin.
@@ -56,162 +50,6 @@ public function testAccess() {
   }
 
   /**
-   * Tests the build() method when a block is empty.
-   *
-   * @covers ::build
-   */
-  public function testBuildEmptyBlock() {
-    $account = $this->prophesize(AccountInterface::class);
-    $block1 = $this->prophesize(BlockPluginInterface::class);
-    $block1->access($account)->willReturn(TRUE);
-
-    // Building a block with empty content.
-    $block1->build()->willReturn(['#cache' => [ 'tags' => [ 0 => 'tag_to_be_merged']]]);
-
-    $context_handler = $this->prophesize(ContextHandlerInterface::class);
-    $uuid_generator = $this->prophesize(UuidInterface::class);
-    $token = $this->prophesize(Token::class);
-
-    $display_variant = new TestBlockDisplayVariant([], '', [], $context_handler->reveal(), $account->reveal(), $uuid_generator->reveal(), $token->reveal());
-
-    // Empty block.
-    $expected_build = [
-      '#markup' => '',
-      '#cache' => [
-        'tags' => [
-          'block_plugin:block_plugin_id',
-          'page:page_id',
-          'tag_to_be_merged',
-        ],
-        'contexts' => [],
-        'max-age' => -1,
-      ],
-    ];
-
-    $build = [
-      '#block_plugin' => $block1->reveal(),
-      '#cache' => [
-        'tags' => [
-          'page:page_id',
-          'block_plugin:block_plugin_id',
-        ],
-      ],
-    ];
-
-    $build = $display_variant->buildBlock($build);
-
-    // Assert that cacheability metadata is merged.
-    $this->assertSame($expected_build, $build);
-  }
-
-  /**
-   * Tests the build() method when blocks can be cached.
-   *
-   * @covers ::build
-   */
-  public function testBuild() {
-    $container = new ContainerBuilder();
-    $cache_contexts = $this->prophesize(CacheContextsManager::class);
-    $container->set('cache_contexts_manager', $cache_contexts->reveal());
-    \Drupal::setContainer($container);
-
-    $account = $this->prophesize(AccountInterface::class);
-
-    // Define one block that allows access, access varies by permissions.
-    $block1 = $this->prophesize(BlockPluginInterface::class);
-    $block1->access($account, TRUE)->willReturn(AccessResult::allowed()->cachePerPermissions());
-    $block1->getConfiguration()->willReturn(['label' => 'Block label']);
-    $block1->getPluginId()->willReturn('block_plugin_id');
-    $block1->getBaseId()->willReturn('block_base_plugin_id');
-    $block1->getDerivativeId()->willReturn('block_derivative_plugin_id');
-    $block1->getCacheTags()->willReturn(['block_plugin1:block_plugin_id']);
-    $block1->getCacheMaxAge()->willReturn(3600);
-    $block1->getCacheContexts()->willReturn(['url']);
-
-    // Define another block that doesn't allow access
-    $block2 = $this->prophesize()->willImplement(ContextAwarePluginInterface::class)->willImplement(BlockPluginInterface::class);
-    $block2->access($account, TRUE)->willReturn(AccessResult::forbidden()->cachePerUser());
-    $block2->getConfiguration()->willReturn([]);
-    $block2->getPluginId()->willReturn('block_plugin_id');
-    $block2->getBaseId()->willReturn('block_base_plugin_id');
-    $block2->getDerivativeId()->willReturn('block_derivative_plugin_id');
-    // The block is not shown, so cacheability metadata is not collected.
-    $block2->getCacheContexts()->shouldNotBeCalled();
-    $block2->getCacheMaxAge()->shouldNotBeCalled();
-    $block2->getCacheTags()->shouldNotBeCalled();
-    $blocks = [
-      'top' => [
-        'block1' => $block1->reveal(),
-        'block2' => $block2->reveal(),
-      ],
-    ];
-    $block_collection = $this->getMockBuilder(BlockPluginCollection::class)
-      ->disableOriginalConstructor()
-      ->getMock();
-    $block_collection->expects($this->once())
-      ->method('getAllByRegion')
-      ->willReturn($blocks);
-
-    $context_handler = $this->prophesize(ContextHandlerInterface::class);
-    $context_handler->applyContextMapping($block2->reveal(), [])->shouldBeCalledTimes(1);
-
-    $uuid_generator = $this->prophesize(UuidInterface::class);
-    $page_title = 'Page title';
-    $token = $this->getMockBuilder(Token::class)
-      ->disableOriginalConstructor()
-      ->getMock();
-    $display_variant = $this->getMockBuilder(BlockDisplayVariant::class)
-      ->setConstructorArgs([['page_title' => $page_title, 'uuid' => 'UUID'], 'test', [], $context_handler->reveal(), $account->reveal(), $uuid_generator->reveal(), $token])
-      ->setMethods(['getBlockCollection', 'renderPageTitle'])
-      ->getMock();
-
-    $page = $this->prophesize(PageInterface::class);
-    $page->id()->willReturn('page_id');
-
-    $display_variant->expects($this->once())
-      ->method('getBlockCollection')
-      ->willReturn($block_collection);
-    $display_variant->expects($this->once())
-      ->method('renderPageTitle')
-      ->with($page_title)
-      ->willReturn($page_title);
-
-    $expected_cache_block1 = [
-      'keys' => ['page_manager_block_display', 'UUID', 'block', 'block1'],
-      'tags' => ['block_plugin1:block_plugin_id'],
-      'contexts' => ['url'],
-      'max-age' => 3600,
-    ];
-
-    // The page cacheability metadata contains the access cacheability metadata
-    // of accessible and non-accessible blocks. Additionally, the cacheability
-    // metadata of accessible blocks is merged to avoid cache redirects when
-    // possible.
-    $expected_cache_page = [
-      'keys' => ['page_manager_block_display', 'UUID'],
-      'contexts' => ['url', 'user', 'user.permissions'],
-      'tags' => ['block_plugin1:block_plugin_id'],
-      'max-age' => 3600,
-    ];
-
-    // Build the variant and ensure that pre_render is set only for the first
-    // block.
-    $build = $display_variant->build();
-    $build = $display_variant->buildRegions($build);
-    $this->assertSame([$display_variant, 'buildBlock'], $build['top']['block1']['#pre_render'][0]);
-    $this->assertTrue(empty($build['top']['block2']));
-    $this->assertSame($expected_cache_block1, $build['top']['block1']['#cache']);
-    $this->assertSame($expected_cache_page, $build['#cache']);
-
-    // Ensure that building the block returns the correct markup.
-    $block1->build()->willReturn([
-      '#markup' => 'block1_build_value',
-    ]);
-    $block1_build = $display_variant->buildBlock($build['top']['block1']);
-    $this->assertSame(['#markup' => 'block1_build_value'], $block1_build['content']);
-  }
-
-  /**
    * Tests the submitConfigurationForm() method.
    *
    * @covers ::submitConfigurationForm
@@ -224,7 +62,7 @@ public function testSubmitConfigurationForm($values) {
     $uuid_generator = $this->prophesize(UuidInterface::class);
     $token = $this->prophesize(Token::class);
 
-    $display_variant = new BlockDisplayVariant([], '', [], $context_handler->reveal(), $account->reveal(), $uuid_generator->reveal(), $token->reveal());
+    $display_variant = new TestBlockDisplayVariant([], '', [], $context_handler->reveal(), $account->reveal(), $uuid_generator->reveal(), $token->reveal());
 
     $form = [];
     $form_state = (new FormState())->setValues($values);
@@ -265,158 +103,14 @@ class TestBlockDisplayVariant extends BlockDisplayVariant {
    * {@inheritdoc}
    */
   public function build() {
-    // Set default page cache keys that include the display.
-    $build['#cache']['keys'] = [
-      'test_block_display',
-      // The UUID of this display.
-      // @todo should have an API for this?
-      $this->configuration['uuid'],
-    ];
-    $build['#pre_render'][] = [$this, 'buildRegions'];
-    return $build;
+    return [];
   }
 
-  /**
-   * #pre_render callback for building the regions.
-   */
-  public function buildRegions(array $build) {
-    $cacheability = CacheableMetadata::createFromRenderArray($build)
-      ->addCacheableDependency($this);
-
-    $contexts = $this->getContexts();
-    foreach ($this->getRegionAssignments() as $region => $blocks) {
-      if (!$blocks) {
-        continue;
-      }
-
-      $region_name = Html::getClass("block-region-$region");
-      $build[$region]['#prefix'] = '<div class="' . $region_name . '">';
-      $build[$region]['#suffix'] = '</div>';
-
-      /** @var $blocks \Drupal\Core\Block\BlockPluginInterface[] */
-      $weight = 0;
-      foreach ($blocks as $block_id => $block) {
-        if ($block instanceof ContextAwarePluginInterface) {
-          $this->contextHandler()->applyContextMapping($block, $contexts);
-        }
-        $access = $block->access($this->account, TRUE);
-        $cacheability->addCacheableDependency($access);
-        if (!$access->isAllowed()) {
-          continue;
-        }
-
-        $block_build = [
-          '#theme' => 'block',
-          '#attributes' => [],
-          '#weight' => $weight++,
-          '#configuration' => $block->getConfiguration(),
-          '#plugin_id' => $block->getPluginId(),
-          '#base_plugin_id' => $block->getBaseId(),
-          '#derivative_plugin_id' => $block->getDerivativeId(),
-          '#block_plugin' => $block,
-          '#pre_render' => [[$this, 'buildBlock']],
-          '#cache' => [
-            'keys' => ['page_manager_block_display', $this->configuration['uuid'], 'block', $block_id],
-            // Each block needs cache tags of the page and the block plugin, as
-            // only the page is a config entity that will trigger cache tag
-            // invalidations in case of block configuration changes.
-            'tags' => Cache::mergeTags($this->getCacheTags(), $block->getCacheTags()),
-            'contexts' => $block->getCacheContexts(),
-            'max-age' => $block->getCacheMaxAge(),
-          ],
-        ];
-
-        // Merge the cacheability metadata of blocks into the page. This helps
-        // to avoid cache redirects if the blocks have more cache contexts than
-        // the page, which the page must respect as well.
-        $cacheability->addCacheableDependency($block);
-
-        $build[$region][$block_id] = $block_build;
-      }
-    }
-
-    $build['#title'] = $this->renderPageTitle($this->configuration['page_title']);
-
-    $cacheability->applyTo($build);
-
-    return $build;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function buildConfigurationForm(array $form, FormStateInterface $form_state) {
-    $form = parent::buildConfigurationForm($form, $form_state);
-
-    // Allow to configure the page title, even when adding a new display.
-    // Default to the page label in that case.
-    $form['page_title'] = [
-      '#type' => 'textfield',
-      '#title' => $this->t('Page title'),
-      '#description' => $this->t('Configure the page title that will be used for this display.'),
-      '#default_value' => $this->configuration['page_title'] ?: '',
-    ];
-
-    return $form;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function submitConfigurationForm(array &$form, FormStateInterface $form_state) {
-    parent::submitConfigurationForm($form, $form_state);
-
-    if ($form_state->hasValue('page_title')) {
-      $this->configuration['page_title'] = $form_state->getValue('page_title');
-    }
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function defaultConfiguration() {
-    return parent::defaultConfiguration() + [
-      'blocks' => [],
-      'selection_conditions' => [],
-      'selection_logic' => 'and',
-      'page_title' => '',
+  public function getRegionNames() {
+    return [
+      'top' => 'Top',
+      'bottom' => 'Bottom',
     ];
   }
 
-  /**
-   * Renders the page title and replaces tokens.
-   *
-   * @param string $page_title
-   *   The page title that should be rendered.
-   *
-   * @return string
-   *   The page title after replacing any tokens.
-   */
-  protected function renderPageTitle($page_title) {
-    $data = $this->getContextAsTokenData();
-    return $this->token->replace($page_title, $data);
-  }
-
-  /**
-   * Returns available context as token data.
-   *
-   * @return array
-   *   An array with token data values keyed by token type.
-   */
-  protected function getContextAsTokenData() {
-    $data = [];
-    foreach ($this->getContexts() as $context) {
-      // @todo Simplify this when token and typed data types are unified in
-      //   https://drupal.org/node/2163027.
-      if (strpos($context->getContextDefinition()->getDataType(), 'entity:') === 0) {
-        $token_type = substr($context->getContextDefinition()->getDataType(), 7);
-        if ($token_type == 'taxonomy_term') {
-          $token_type = 'term';
-        }
-        $data[$token_type] = $context->getContextValue();
-      }
-    }
-    return $data;
-  }
 }
-