public Builder clearStartTime() {
      bitField0_ = (bitField0_ & ~0x00000002);
      startTime_ = null;
      if (startTimeBuilder_ != null) {
        startTimeBuilder_.dispose();
        startTimeBuilder_ = null;
      }
      onChanged();
      return this;
    }
<pre>
Time when the request was received.
</pre>

<code>.google.protobuf.Timestamp start_time = 2;</code>
java-speech/proto-google-cloud-speech-v1p1beta1/src/main/java/com/google/cloud/speech/v1p1beta1/LongRunningRecognizeMetadata.java