class AbstractMeta implements IChanged, IUndo, IVariables, IEngineMeta, INamedParams, IAttributes, ILoggingObject {

  @Override
  public boolean getBooleanValueOfVariable( String variableName, boolean defaultValue ) {
    if ( !Utils.isEmpty( variableName ) ) {
      String value = environmentSubstitute( variableName );
      if ( !Utils.isEmpty( value ) ) {
        return ValueMetaString.convertStringToBoolean( value );
      }
    }
    return defaultValue;
  }

}