code: public static ExpressionArithmeticOp add(Expression left, Expression right) {
  		return new ExpressionArithmeticOp(ArithmeticOperation.ADD, left, right);
  	}
docs: Returns sum of arguments
  
  @param left  first argument which will be added
  @param right second argument which will be added
  @return new instance of the ExpressionArithmeticOp