Appends a (empty) recap message that will be published under the specified 'topic' to the event referenced by this EventFormatter. Specifies the optional 'cid' if this recap message is added in response to a 'TopicRecap' message. After a message has been appended its elements can be set using the various 'SetElement' methods. It is an error to create append a recap message to an admin event.

Appends a (empty) recap message that will be published under the specified 'topic' to the event referenced by this EventFormatter. Specifies the optional 'cid' if this recap message is added in response to a 'TopicRecap' message. After a message has been appended its elements can be set using the various 'SetElement' methods. It is an error to create append a recap message to an admin event. The behavior is undefined unless the 'sequenceNumber' is greater (unless the value wrapped) than the last value used in any previous message on this 'topic'.