func (l *PeerList) Len() int {
	l.RLock()
	defer l.RUnlock()
	return l.peerHeap.Len()
}
func (l *PeerList) Len() int {
	l.RLock()
	defer l.RUnlock()
	return l.peerHeap.Len()
}
func ( l * PeerList ) Len ( ) int { l . RLock ( ) defer l . RUnlock ( ) return l . peerHeap . Len ( ) }
// Len returns the length of the PeerList.
Len returns the length of the PeerList .