def mod(other)
      if other.is_a?(Number)
        return Number.new(Float::NAN) if other.value == 0
        operate(other, :%)
      else
        raise NoMethodError.new(nil, :mod)
      end
    end
def mod(other)
      if other.is_a?(Number)
        return Number.new(Float::NAN) if other.value == 0
        operate(other, :%)
      else
        raise NoMethodError.new(nil, :mod)
      end
    end
The SassScript `%` operation.

 @param other [Number] The right-hand side of the operator
 @return [Number] This number modulo the other
 @raise [NoMethodError] if `other` is an invalid type
 @raise [Sass::UnitConversionError] if `other` has incompatible units