public Builder mergeUpcomingMaintenance(
        com.google.cloud.tpu.v2alpha1.UpcomingMaintenance value) {
      if (upcomingMaintenanceBuilder_ == null) {
        if (((bitField0_ & 0x08000000) != 0)
            && upcomingMaintenance_ != null
            && upcomingMaintenance_
                != com.google.cloud.tpu.v2alpha1.UpcomingMaintenance.getDefaultInstance()) {
          getUpcomingMaintenanceBuilder().mergeFrom(value);
        } else {
          upcomingMaintenance_ = value;
        }
      } else {
        upcomingMaintenanceBuilder_.mergeFrom(value);
      }
      if (upcomingMaintenance_ != null) {
        bitField0_ |= 0x08000000;
        onChanged();
      }
      return this;
    }
<pre>
Output only. Upcoming maintenance on this TPU node.
</pre>

<code>
.google.cloud.tpu.v2alpha1.UpcomingMaintenance upcoming_maintenance = 51 [(.google.api.field_behavior) = OUTPUT_ONLY];
</code>
java-tpu/proto-google-cloud-tpu-v2alpha1/src/main/java/com/google/cloud/tpu/v2alpha1/Node.java