private void ensureStepsIsMutable() {
      if (!((bitField0_ & 0x00000200) != 0)) {
        steps_ = new java.util.ArrayList<com.google.cloud.vmmigration.v1.CutoverStep>(steps_);
        bitField0_ |= 0x00000200;
      }
    }
<pre>
Output only. A message providing possible extra details about the current
state.
</pre>

<code>string state_message = 10 [(.google.api.field_behavior) = OUTPUT_ONLY];</code>

@param value The bytes for stateMessage to set.
@return This builder for chaining.
java-vmmigration/proto-google-cloud-vmmigration-v1/src/main/java/com/google/cloud/vmmigration/v1/CutoverJob.java