@java.lang.Override
  public java.lang.String getEngineVersion() {
    java.lang.Object ref = engineVersion_;
    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();
      engineVersion_ = s;
      return s;
    }
  }
<pre>
Optional. Immutable. Engine version of the instance.
</pre>

<code>
string engine_version = 15 [(.google.api.field_behavior) = OPTIONAL, (.google.api.field_behavior) = IMMUTABLE];
</code>

@return The engineVersion.
java-valkey/proto-google-cloud-valkey-v1beta/src/main/java/com/google/cloud/memorystore/v1beta/Instance.java