code: def to_api_data(self, restrict_keys=None):
          
          cc = self.parent._cc  # alias
          data = {
              cc('bold'): self._bold,
              cc('color'): self._color,
              cc('italic'): self._italic,
              cc('name'): self._name,
              cc('size'): self._size,
              cc('underline'): self._underline
          }
  
          if restrict_keys:
              for key in list(data.keys()):
                  if key not in restrict_keys:
                      del data[key]
          return data
docs: Returns a dict to communicate with the server
  
          :param restrict_keys: a set of keys to restrict the returned data to
          :rtype: dict