reverted:
--- b/core/lib/Drupal/Core/TypedData/Validation/PropertyContainerMetadata.php
+++ a/core/lib/Drupal/Core/TypedData/Validation/PropertyContainerMetadata.php
@@ -9,13 +9,13 @@
 
 use Drupal\Core\TypedData\ComplexDataInterface;
 use Drupal\Core\TypedData\ListInterface;
+use Symfony\Component\Validator\PropertyMetadataContainerInterface;
-use Symfony\Component\Validator\Mapping\ClassMetadataInterface;
 use Symfony\Component\Validator\ValidationVisitorInterface;
 
 /**
  * Typed data implementation of the validator MetadataInterface.
  */
+class PropertyContainerMetadata extends Metadata implements PropertyMetadataContainerInterface {
-class PropertyContainerMetadata extends Metadata implements ClassMetadataInterface {
 
   /**
    * Overrides Metadata::accept().
@@ -65,63 +65,4 @@
       throw new \LogicException("There are no known properties.");
     }
   }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function getClassName()
-    {
-        // TODO: Implement getClassName() method.
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function getConstrainedProperties()
-    {
-        // TODO: Implement getConstrainedProperties() method.
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function hasGroupSequence()
-    {
-        // TODO: Implement hasGroupSequence() method.
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function getGroupSequence()
-    {
-        // TODO: Implement getGroupSequence() method.
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function isGroupSequenceProvider()
-    {
-        // TODO: Implement isGroupSequenceProvider() method.
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function getCascadingStrategy()
-    {
-        // TODO: Implement getCascadingStrategy() method.
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function getTraversalStrategy()
-    {
-        // TODO: Implement getTraversalStrategy() method.
-    }
-
-
 }
-
only in patch2:
unchanged:
--- a/core/lib/Drupal/Core/TypedData/Validation/PropertyContainerMetadata.php
+++ b/core/lib/Drupal/Core/TypedData/Validation/ClassMetadata.php
@@ -2,20 +2,20 @@
 
 /**
  * @file
- * Contains \Drupal\Core\TypedData\Validation\PropertyContainerMetadata.
+ * Contains \Drupal\Core\TypedData\Validation\ClassMetadata.
  */
 
 namespace Drupal\Core\TypedData\Validation;
 
 use Drupal\Core\TypedData\ComplexDataInterface;
 use Drupal\Core\TypedData\ListInterface;
-use Symfony\Component\Validator\PropertyMetadataContainerInterface;
+use Symfony\Component\Validator\Mapping\ClassMetadataInterface;
 use Symfony\Component\Validator\ValidationVisitorInterface;
 
 /**
  * Typed data implementation of the validator MetadataInterface.
  */
-class PropertyContainerMetadata extends Metadata implements PropertyMetadataContainerInterface {
+class ClassMetadata extends Metadata implements ClassMetadataInterface {
 
   /**
    * Overrides Metadata::accept().
@@ -65,4 +65,62 @@ public function getPropertyMetadata($property_name) {
       throw new \LogicException("There are no known properties.");
     }
   }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getClassName() {
+    // TODO: Implement getClassName() method.
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getConstraints() {
+    // TODO: Implement getClassName() method.
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getConstrainedProperties() {
+    // TODO: Implement getConstrainedProperties() method.
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function hasGroupSequence() {
+    // TODO: Implement hasGroupSequence() method.
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getGroupSequence() {
+    // TODO: Implement getGroupSequence() method.
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function isGroupSequenceProvider() {
+    // TODO: Implement isGroupSequenceProvider() method.
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getCascadingStrategy() {
+    // TODO: Implement getCascadingStrategy() method.
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getTraversalStrategy() {
+    // TODO: Implement getTraversalStrategy() method.
+  }
+
+
 }
only in patch2:
unchanged:
--- a/core/lib/Drupal/Core/TypedData/Validation/MetadataFactory.php
+++ b/core/lib/Drupal/Core/TypedData/Validation/MetadataFactory.php
@@ -31,7 +31,7 @@ public function getMetadataFor($typed_data, $name = '') {
       throw new \InvalidArgumentException('The passed value must be a typed data object.');
     }
     $is_container = $typed_data instanceof ComplexDataInterface || $typed_data instanceof ListInterface;
-    $class = '\Drupal\Core\TypedData\Validation\\' . ($is_container ? 'PropertyContainerMetadata' : 'Metadata');
+    $class = '\Drupal\Core\TypedData\Validation\\' . ($is_container ? 'ClassMetadata' : 'Metadata');
     return new $class($typed_data, $name, $this);
   }
 
only in patch2:
unchanged:
--- a/core/lib/Drupal/Core/Validation/Plugin/Validation/Constraint/ComplexDataConstraintValidator.php
+++ b/core/lib/Drupal/Core/Validation/Plugin/Validation/Constraint/ComplexDataConstraintValidator.php
@@ -38,7 +38,7 @@ public function validate($value, Constraint $constraint) {
         $property = $property->getValue();
       }
       elseif ($property->isEmpty()) {
-        // @see \Drupal\Core\TypedData\Validation\PropertyContainerMetadata::accept();
+        // @see \Drupal\Core\TypedData\Validation\ClassMetadata::accept();
         $property = NULL;
       }
       $this->context->validateValue($property, $constraints, $name, $group);