function proxyaddr(req, trust) {
  if (!req) {
    throw new TypeError('req argument is required');
  }

  if (!trust) {
    throw new TypeError('trust argument is required');
  }

  var addrs = alladdrs(req, trust);
  var addr = addrs[addrs.length - 1];

  return addr;
}
Determine address of proxied request.

@param {Object} request
@param {Function|Array|String} trust
@api public