@java.lang.Override
  public com.google.cloud.tpu.v2alpha1.CustomerEncryptionKey getCustomerEncryptionKey() {
    return customerEncryptionKey_ == null
        ? com.google.cloud.tpu.v2alpha1.CustomerEncryptionKey.getDefaultInstance()
        : customerEncryptionKey_;
  }
<pre>
Optional. Customer encryption key for boot disk.
</pre>

<code>
.google.cloud.tpu.v2alpha1.CustomerEncryptionKey customer_encryption_key = 1 [(.google.api.field_behavior) = OPTIONAL];
</code>

@return The customerEncryptionKey.
java-tpu/proto-google-cloud-tpu-v2alpha1/src/main/java/com/google/cloud/tpu/v2alpha1/BootDiskConfig.java