docs: def enter(self, container_alias):
  
          '''
              a method to open up a terminal inside a running container
  
          :param container_alias: string with name or id of container 
          :return: None
          '''
          
          title = '%s.enter' % self.__class__.__name__
  
      # validate inputs
          input_fields = {
              'container_alias': container_alias
          }
          for key, value in input_fields.items():
              object_title = '%s(%s=%s)' % (title, key, str(value))
              self.fields.validate(value, '.%s' % key, object_title)
      
      # compose system command
          from os import system
          sys_cmd = 'docker exec -it %s sh' % container_alias
          if self.localhost.os.sysname in ('Windows'):
              sys_cmd = 'winpty %s' % sys_cmd
  
      # open up terminal
          system(sys_cmd)