docs: def quotation_markers(self, value):
          """
          Setter for **self.__quotation_markers** attribute.
  
          :param value: Attribute value.
          :type value: tuple or list
          """
  
          if value is not None:
              assert type(value) in (tuple, list), "'{0}' attribute: '{1}' type is not 'tuple' or 'list'!".format(
                  "quotation_markers", value)
              for element in value:
                  assert type(element) is unicode, "'{0}' attribute: '{1}' type is not 'unicode'!".format(
                      "quotation_markers", element)
                  assert len(element) == 1, "'{0}' attribute: '{1}' has multiples characters!".format("quotation_markers",
                                                                                                      element)
                  assert not re.search(r"\w", element), "'{0}' attribute: '{1}' is an alphanumeric character!".format(
                      "quotation_markers", element)
          self.__quotation_markers = value