@CanIgnoreReturnValue
  KmsClient withCloudKms(CloudKMS cloudKms) {
      this.cloudKms = cloudKms;
      return this;
  }
Specifies the {@link com.google.api.services.cloudkms.v1.CloudKMS} object to be used. Only used
for testing.
java_src/src/main/java/com/google/crypto/tink/integration/gcpkms/GcpKmsClient.java