code: def _get_valid_port(self, port):
          
          if '/' in port:
              port, protocol = port.split('/')
          else:
              protocol = 'tcp'
  
          try:
              int(port)
          except ValueError:
              raise ValueError("{0} isn't a valid port number.".format(port))
  
          if protocol not in ('tcp', 'udp'):
              raise ValueError("exposed ports only supports udp or tcp. {0} was passed".format(protocol))
  
          return "{0}/{1}".format(port, protocol)
docs: :param port:
          :return "port/protocol":