def remove_item(self, jid, callback = None, error_callback = None):
item = self.roster[jid]<EOL>if jid not in self.roster:<EOL><INDENT>raise KeyError(jid)<EOL><DEDENT>item = RosterItem(jid, subscription = "<STR_LIT>")<EOL>self._roster_set(item, callback, error_callback)<EOL>
Remove a contact from the roster.

        :Parameters:
            - `jid`: contact's jid
            - `callback`: function to call when the request succeeds. It should
              accept a single argument - a `RosterItem` describing the
              requested change
            - `error_callback`: function to call when the request fails. It
              should accept a single argument - an error stanza received
              (`None` in case of timeout)
        :Types:
            - `jid`: `JID`