public IPRangeNode findFast(String addr){
  InetAddress iaddr;
  try {
    iaddr=InetAddress.getByName(addr);
  }
 catch (  UnknownHostException ex) {
    return null;
  }
  return findFast(iaddr);
}

public IPRangeNode findFast ( String addr ) { InetAddress iaddr ; try { iaddr = InetAddress . getByName ( addr ) ; } catch ( UnknownHostException ex ) { return null ; } return findFast ( iaddr ) ; }
performs a binary search over sorted list
