// This file is part of the go-ethereum library.//// The go-ethereum library is free software: you can redistribute it and/or modify// it under the terms of the GNU Lesser General Public License as published by// the Free Software Foundation, either version 3 of the License, or// (at your option) any later version.//// The go-ethereum library is distributed in the hope that it will be useful,// but WITHOUT ANY WARRANTY; without even the implied warranty of// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the// GNU Lesser General Public License for more details.//// You should have received a copy of the GNU Lesser General Public License// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.packagenetutilimport"net"// AddrIP gets the IP address contained in addr. It returns nil if no address is present.funcAddrIP(addrnet.Addr)net.IP{switcha:=addr.(type){case*net.IPAddr:returna.IPcase*net.TCPAddr:returna.IPcase*net.UDPAddr:returna.IPdefault:returnnil}}