public com.google.protobuf.Timestamp getEndTime() {
          if (endTimeBuilder_ == null) {
            return endTime_ == null ? com.google.protobuf.Timestamp.getDefaultInstance() : endTime_;
          } else {
            return endTimeBuilder_.getMessage();
          }
        }
<pre>
Optional. The ending timestamp for messages to import.
</pre>

<code>.google.protobuf.Timestamp end_time = 3 [(.google.api.field_behavior) = OPTIONAL];
</code>

@return The endTime.
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/SlackSource.java