docs: def verify_port_map(plugin):
      """
      extra validation /
      PB2 sees empty lists the same as non-existant lists
      :param plugin:
      :return:
      """
      result = True
      ex_ports = plugin.get(EX_PORTS_KEY)
      result &= isinstance(ex_ports, list) and verify_ports(ex_ports)
      in_ports = plugin.get(IN_PORTS_KEY)
      result &= isinstance(in_ports, list) and verify_ports(in_ports)
      env_list = plugin.get(ENV_KEY)
      result &= isinstance(env_list, list) and verify_environment(env_list)
      if result:
          result &= len(ex_ports) == len(in_ports)
      return result