@java.lang.Override
    public java.lang.String getKmsKey() {
      java.lang.Object ref = kmsKey_;
      if (ref instanceof java.lang.String) {
        return (java.lang.String) ref;
      } else {
        com.google.protobuf.ByteString bs = (com.google.protobuf.ByteString) ref;
        java.lang.String s = bs.toStringUtf8();
        kmsKey_ = s;
        return s;
      }
    }
<pre>
Immutable. The name of the Google Cloud KMS encryption key. For example,
`"projects/PROJECT_ID/locations/REGION/keyRings/KEY_RING/cryptoKeys/KEY_NAME"`.
The key must be in the same region as the workstation configuration.
</pre>

<code>string kms_key = 1 [(.google.api.field_behavior) = IMMUTABLE];</code>

@return The kmsKey.
java-workstations/proto-google-cloud-workstations-v1/src/main/java/com/google/cloud/workstations/v1/WorkstationConfig.java