public Builder setGcePd(
          com.google.cloud.workstations.v1.WorkstationConfig.PersistentDirectory
                  .GceRegionalPersistentDisk
              value) {
        if (gcePdBuilder_ == null) {
          if (value == null) {
            throw new NullPointerException();
          }
          directoryType_ = value;
          onChanged();
        } else {
          gcePdBuilder_.setMessage(value);
        }
        directoryTypeCase_ = 2;
        return this;
      }
<pre>
A PersistentDirectory backed by a Compute Engine persistent disk.
</pre>

<code>
.google.cloud.workstations.v1.WorkstationConfig.PersistentDirectory.GceRegionalPersistentDisk gce_pd = 2;
</code>
java-workstations/proto-google-cloud-workstations-v1/src/main/java/com/google/cloud/workstations/v1/WorkstationConfig.java