public Builder mergeStartTime(com.google.protobuf.Timestamp value) {
      if (startTimeBuilder_ == null) {
        if (((bitField0_ & 0x00000001) != 0)
            && startTime_ != null
            && startTime_ != com.google.protobuf.Timestamp.getDefaultInstance()) {
          getStartTimeBuilder().mergeFrom(value);
        } else {
          startTime_ = value;
        }
      } else {
        startTimeBuilder_.mergeFrom(value);
      }
      if (startTime_ != null) {
        bitField0_ |= 0x00000001;
        onChanged();
      }
      return this;
    }
<pre>
Time when the request was received.
</pre>

<code>.google.protobuf.Timestamp start_time = 1;</code>
java-texttospeech/proto-google-cloud-texttospeech-v1/src/main/java/com/google/cloud/texttospeech/v1/SynthesizeLongAudioMetadata.java