public Builder mergeEndTime(com.google.protobuf.Timestamp value) {
          if (endTimeBuilder_ == null) {
            if (((bitField0_ & 0x00000004) != 0)
                && endTime_ != null
                && endTime_ != com.google.protobuf.Timestamp.getDefaultInstance()) {
              getEndTimeBuilder().mergeFrom(value);
            } else {
              endTime_ = value;
            }
          } else {
            endTimeBuilder_.mergeFrom(value);
          }
          if (endTime_ != null) {
            bitField0_ |= 0x00000004;
            onChanged();
          }
          return this;
        }
<pre>
Optional. The ending timestamp for messages to import.
</pre>

<code>.google.protobuf.Timestamp end_time = 3 [(.google.api.field_behavior) = OPTIONAL];
</code>
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/SlackSource.java