@staticmethod
def append_closed_ports(port_list):
    """ Having a list of open/filtered ports, it creates a list with the rest of non responding ports
        from 0 to 65535, directly classifying them as closed ports.

            :param port_list: List of open/filtered ports
            :type port_list: list
            :return: List with all supposed closed ports
            :rtype: list
        """
    closed_ports = []
    all_ports = range(1, 65536)
    for port in all_ports:
        if port not in port_list:
            closed_ports.append(port)
    return closed_ports
