public Builder setStartTime(com.google.protobuf.Timestamp.Builder builderForValue) {
      if (startTimeBuilder_ == null) {
        startTime_ = builderForValue.build();
      } else {
        startTimeBuilder_.setMessage(builderForValue.build());
      }
      bitField0_ |= 0x00000008;
      onChanged();
      return this;
    }
<pre>
The time the operation was started.
</pre>

<code>.google.protobuf.Timestamp start_time = 4;</code>
java-vmmigration/proto-google-cloud-vmmigration-v1/src/main/java/com/google/cloud/vmmigration/v1/UpgradeStatus.java