code: func (t *Torrent) deleteConnection(c *connection) (ret bool) {
  	if !c.closed.IsSet() {
  		panic("connection is not closed")
  		// There are behaviours prevented by the closed state that will fail
  		// if the connection has been deleted.
  	}
  	_, ret = t.conns[c]
  	delete(t.conns, c)
  	torrent.Add("deleted connections", 1)
  	c.deleteAllRequests()
  	if len(t.conns) == 0 {
  		t.assertNoPendingRequests()
  	}
  	return
  }
docs: // Returns true if connection is removed from torrent.Conns.