private com.google.protobuf.MapField<java.lang.String, java.lang.String>
      internalGetEngineConfigs() {
    if (engineConfigs_ == null) {
      return com.google.protobuf.MapField.emptyMapField(
          EngineConfigsDefaultEntryHolder.defaultEntry);
    }
    return engineConfigs_;
  }
<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 bytes for engineVersion.
java-valkey/proto-google-cloud-valkey-v1beta/src/main/java/com/google/cloud/memorystore/v1beta/Instance.java