docs: def ip(self):
  
          '''
              a method to retrieve the ip of system running docker
  
          :return: string with ip address of system
          '''
  
          if self.localhost.os.sysname == 'Windows' and float(self.localhost.os.release) < 10:
              sys_cmd = 'docker-machine ip %s' % self.vbox
              system_ip = self.command(sys_cmd).replace('\n','')
          else:
              system_ip = self.localhost.ip
  
          return system_ip