private com.google.protobuf.SingleFieldBuilderV3<
              com.google.cloud.workstations.v1beta.WorkstationConfig.EphemeralDirectory
                  .GcePersistentDisk,
              com.google.cloud.workstations.v1beta.WorkstationConfig.EphemeralDirectory
                  .GcePersistentDisk.Builder,
              com.google.cloud.workstations.v1beta.WorkstationConfig.EphemeralDirectory
                  .GcePersistentDiskOrBuilder>
          getGcePdFieldBuilder() {
        if (gcePdBuilder_ == null) {
          if (!(directoryTypeCase_ == 3)) {
            directoryType_ =
                com.google.cloud.workstations.v1beta.WorkstationConfig.EphemeralDirectory
                    .GcePersistentDisk.getDefaultInstance();
          }
          gcePdBuilder_ =
              new com.google.protobuf.SingleFieldBuilderV3<
                  com.google.cloud.workstations.v1beta.WorkstationConfig.EphemeralDirectory
                      .GcePersistentDisk,
                  com.google.cloud.workstations.v1beta.WorkstationConfig.EphemeralDirectory
                      .GcePersistentDisk.Builder,
                  com.google.cloud.workstations.v1beta.WorkstationConfig.EphemeralDirectory
                      .GcePersistentDiskOrBuilder>(
                  (com.google.cloud.workstations.v1beta.WorkstationConfig.EphemeralDirectory
                          .GcePersistentDisk)
                      directoryType_,
                  getParentForChildren(),
                  isClean());
          directoryType_ = null;
        }
        directoryTypeCase_ = 3;
        onChanged();
        return gcePdBuilder_;
      }
<pre>
An EphemeralDirectory backed by a Compute Engine persistent disk.
</pre>

<code>
.google.cloud.workstations.v1beta.WorkstationConfig.EphemeralDirectory.GcePersistentDisk gce_pd = 3;
</code>
java-workstations/proto-google-cloud-workstations-v1beta/src/main/java/com/google/cloud/workstations/v1beta/WorkstationConfig.java