code: func (p *prefixTrie) Contains(ip net.IP) (bool, error) {
  	nn := rnet.NewNetworkNumber(ip)
  	if nn == nil {
  		return false, ErrInvalidNetworkNumberInput
  	}
  	return p.contains(nn)
  }
docs: // Contains returns boolean indicating whether given ip is contained in any
  // of the inserted networks.