code: def int_to_roman(integer):
      
      if not isinstance(integer, int):
          raise ValueError("Input integer must be of type int")
      output = []
      while integer > 0:
          for r, i in sorted(_roman_dict.items(),
                             key=lambda x: x[1], reverse=True):
              while integer >= i:
                  output.append(r)
                  integer -= i
      return "".join(output)
docs: Convert an integer into a string of roman numbers.
  
      .. code: python
  
          reusables.int_to_roman(445)
          # 'CDXLV'
  
  
      :param integer:
      :return: roman string