code: def dict_key(self):
          
          while True:
              token = self.next()
              t_value = token["value"]
              if t_value == "\n":
                  continue
              if t_value == "}":
                  raise self.ParseEnd()
              if token["type"] == "literal":
                  return self.make_value(t_value)
              self.error("Invalid Key")
docs: Find the next key in a dict.  We skip any newlines and check for if the
          dict has ended.