public Builder clearStartTime() {
      bitField0_ = (bitField0_ & ~0x00000020);
      startTime_ = null;
      if (startTimeBuilder_ != null) {
        startTimeBuilder_.dispose();
        startTimeBuilder_ = null;
      }
      onChanged();
      return this;
    }
<pre>
The time the step has started.
</pre>

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