def <<(other)
      case other
      when String
        other.each_char do |char|
          byte = char_to_byte(char)

          @chars[byte] = char
          super(byte)
        end

        return self
      when Integer
        super(other)
      else
        raise(TypeError,"can only append Strings and Integers")
      end
    end
def <<(other)
      case other
      when String
        other.each_char do |char|
          byte = char_to_byte(char)

          @chars[byte] = char
          super(byte)
        end

        return self
      when Integer
        super(other)
      else
        raise(TypeError,"can only append Strings and Integers")
      end
    end
Adds a character to the set.

 @param [String, Integer] other
   The character(s) or byte to add.

 @return [CharSet]
   The modified character set.

 @raise [TypeError]
   The argument was not a {String} or {Integer}.

 @since 0.2.1