public Builder clearPreparingVmDisks() {
      if (preparingVmDisksBuilder_ == null) {
        if (stepCase_ == 6) {
          stepCase_ = 0;
          step_ = null;
          onChanged();
        }
      } else {
        if (stepCase_ == 6) {
          stepCase_ = 0;
          step_ = null;
        }
        preparingVmDisksBuilder_.clear();
      }
      return this;
    }
<pre>
Preparing VM disks step.
</pre>

<code>.google.cloud.vmmigration.v1.PreparingVMDisksStep preparing_vm_disks = 6;</code>
java-vmmigration/proto-google-cloud-vmmigration-v1/src/main/java/com/google/cloud/vmmigration/v1/CutoverStep.java