@@ -0,0 +1,1097 @@
+// Copyright 2020 Google LLC%0A//%0A// Licensed under the Apache License, Version 2.0 (the %22License%22);%0A// you may not use this file except in compliance with the License.%0A// You may obtain a copy of the License at%0A//%0A//     https://www.apache.org/licenses/LICENSE-2.0%0A//%0A// Unless required by applicable law or agreed to in writing, software%0A// distributed under the License is distributed on an %22AS IS%22 BASIS,%0A// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.%0A// See the License for the specific language governing permissions and%0A// limitations under the License.%0A%0Apackage com.google.lecturechat.data.constants;%0A%0A/** Specifies the kind and property names to use for event entities in the datastore database. */%0Apublic enum MessageEntity %7B%0A  KIND(%22Message%22),%0A  CONTENT_PROPERTY(%22content%22),%0A  TIMESTAMP_PROPERTY(%22timestamp%22),%0A  AUTHOR_PROPERTY(%22author%22),%0A%0A  /* Labels comments and properties of events in the database. */%0A  private final String label;%0A%0A  private MessageEntity(String label) %7B%0A    this.label = label;%0A  %7D%0A%0A  public String getLabel() %7B%0A    return label;%0A  %7D%0A%7D%0A

Add message entity constants