code: def copy(self,
               fitness_function=None,
               decode_function=None,
               fitness_args=None,
               decode_args=None,
               fitness_kwargs=None,
               decode_kwargs=None):
          
          if fitness_function is None:
              fitness_function = self._fitness_function
          if decode_function is None:
              decode_function = self._decode_function
          if fitness_args is None:
              fitness_args = self._fitness_args
          if decode_args is None:
              decode_args = self._decode_args
          if fitness_kwargs is None:
              fitness_kwargs = self._fitness_kwargs
          if decode_kwargs is None:
              decode_kwargs = self._decode_kwargs
  
          return Problem(
              fitness_function,
              decode_function=decode_function,
              fitness_args=fitness_args,
              decode_args=decode_args,
              fitness_kwargs=fitness_kwargs,
              decode_kwargs=decode_kwargs)
docs: Return a copy of this problem.
  
          Optionally replace this problems arguments with those passed in.