code: def parse(self, fp, headersonly=False):
          
          feedparser = FeedParser(self._class, policy=self.policy)
          if headersonly:
              feedparser._set_headersonly()
          while True:
              data = fp.read(8192)
              if not data:
                  break
              feedparser.feed(data)
          return feedparser.close()
docs: Create a message structure from the data in a file.
  
          Reads all the data from the file and returns the root of the message
          structure.  Optional headersonly is a flag specifying whether to stop
          parsing after reading the headers or not.  The default is False,
          meaning it parses the entire contents of the file.