fails:TCPServer.new binds to a host and a port
fails:TCPServer.new binds to localhost and a port with either IPv4 or IPv6
fails:TCPServer.new binds to INADDR_ANY if the hostname is empty
fails:TCPServer.new binds to INADDR_ANY if the hostname is empty and the port is a string
fails:TCPServer.new coerces port to string, then determines port from that number or service name
fails:TCPServer.new raises Errno::EADDRNOTAVAIL when the adress is unknown
fails:TCPServer.new raises a SocketError when the host is unknown
fails:TCPServer.new raises Errno::EADDRINUSE when address is already in use
fails:TCPServer.new sets SO_REUSEADDR on the resulting server
