+ * Refer to the parent class for configuration keys:
+ * \Drupal\migrate\Plugin\migrate\destination\EntityContentBase
+ *
+ * Entity revisions can only be migrated after the entity to which the revisions
+ * belong has been migrated. For example, revisions of a given content type can
+ * be migrated only after the nodes of that content type have been migrated.
+ *
+ * In order to avoid revision ID conflicts, make sure that the entity migration
+ * also includes the revision ID. If the entity migration did not include the
+ * revision ID, the entity would get the next available revision ID (1 when
+ * migrating to a clean database). Then, when revisions are migrated after the
+ * entities, the revision IDs would almost certainly collide.
+ *
+ * The examples below contain simple node and node revision migrations. The
+ * examples use the EmbeddedDataSource source plugin for the sake of
+ * simplicity. The important part of both examples is the 'vid' property, which
+ * is the revision ID for nodes.
+ *
+ * Example of 'article' node migration, which must be executed before the
+ * 'article' revisions.
+ * @code
+ * id: custom_article_migration
+ * label: 'Custom article migration'
+ * source:
+ * plugin: embedded_data
+ * data_rows:
+ * -
+ * nid: 1
+ * vid: 2
+ * revision_timestamp: 1514661000
+ * revision_log: 'Second revision'
+ * title: 'Current title'
+ * content: '<p>Current content</p>'
+ * ids:
+ * nid:
+ * type: integer
+ * process:
+ * nid: nid
+ * vid: vid
+ * revision_timestamp: revision_timestamp
+ * revision_log: revision_log
+ * title: title
+ * 'body/0/value': content
+ * 'body/0/format':
+ * plugin: default_value
+ * default_value: basic_html
+ * destination:
+ * plugin: entity:node
+ * default_bundle: article
+ * @endcode
+ *
+ * Example of the corresponding node revision migration, which must be executed
+ * after the above migration.
+ * @code
+ * id: custom_article_revision_migration
+ * label: 'Custom article revision migration'
+ * source:
+ * plugin: embedded_data
+ * data_rows:
+ * -
+ * nid: 1
+ * vid: 1
+ * revision_timestamp: 1514660000
+ * revision_log: 'First revision'
+ * title: 'Previous title'
+ * content: '<p>Previous content</p>'
+ * ids:
+ * nid:
+ * type: integer
+ * process:
+ * nid:
+ * plugin: migration_lookup
+ * migration: custom_article_migration
+ * source: nid
+ * vid: vid
+ * revision_timestamp: revision_timestamp
+ * revision_log: revision_log
+ * title: title
+ * 'body/0/value': content
+ * 'body/0/format':
+ * plugin: default_value
+ * default_value: basic_html
+ * destination:
+ * plugin: entity_revision:node
+ * default_bundle: article
+ * migration_dependencies:
+ * required:
+ * - custom_article_migration
+ * @endcode
+ *