def handle_POST(self, environ, start_response):
        """Handles the HTTP POST request.

        Attempts to interpret all HTTP POST requests as XML-RPC calls,
        which are forwarded to the server's _dispatch method for handling.

        Most code taken from SimpleXMLRPCServer with modifications for wsgi and my custom dispatcher.
        """

        try:
            # Get arguments by reading body of request.
            # We read this in chunks to avoid straining
            # socket.read(); around the 10 or 15Mb mark, some platforms
            # begin to have problems (bug #792570).

            length = int(environ['CONTENT_LENGTH'])
            data = environ['wsgi.input'].read(length)

            # In previous versions of SimpleXMLRPCServer, _dispatch
            # could be overridden in this class, instead of in
            # SimpleXMLRPCDispatcher. To maintain backwards compatibility,
            # check to see if a subclass implements _dispatch and
            # using that method if present.
            response = self.dispatcher._marshaled_dispatch(
                data, getattr(self.dispatcher, '_dispatch', None)
            )
            response += b'\n'
        except Exception as e:  # This should only happen if the module is buggy
            # internal error, report as HTTP server error
            logger.exception(e)
            start_response("500 Server error", [('Content-Type', 'text/plain')])
            return []
        else:
            # got a valid XML RPC response
            start_response("200 OK", [('Content-Type', 'text/xml'), ('Content-Length', str(len(response)),)])
            return [response]
Handles the HTTP POST request.

        Attempts to interpret all HTTP POST requests as XML-RPC calls,
        which are forwarded to the server's _dispatch method for handling.

        Most code taken from SimpleXMLRPCServer with modifications for wsgi and my custom dispatcher.
        
pyspider/libs/wsgi_xmlrpc.py