code: def parse_docstring(self):
          
          self.log.debug(
              "parsing docstring, token is %r (%s)", self.current.kind, self.current.value
          )
          while self.current.kind in (tk.COMMENT, tk.NEWLINE, tk.NL):
              self.stream.move()
              self.log.debug(
                  "parsing docstring, token is %r (%s)",
                  self.current.kind,
                  self.current.value,
              )
          if self.current.kind == tk.STRING:
              docstring = self.current.value
              self.stream.move()
              return docstring
          return None
docs: Parse a single docstring and return its value.