@NotNull
  public static GrExpression unparenthesize(@NotNull GrExpression expression) {
    GrExpression currentExpression = expression;
    while (currentExpression instanceof GrParenthesizedExpression) {
      GrExpression operand = ((GrParenthesizedExpression)currentExpression).getOperand();
      if (operand != null) {
        currentExpression = operand;
      } else {
        return currentExpression;
      }
    }
    return currentExpression;
  }
@NotNull
  public static GrExpression unparenthesize(@NotNull GrExpression expression)