text: from django.db import models
  from django.utils.translation import ugettext_lazy as _
  
  from ..generic.models import TimestampUserLogModel
  
  
  class Collection(TimestampUserLogModel):
      name = models.CharField(
          max_length=256,
          verbose_name=_("Name"),
          help_text=_("Collection's name."),
      )
      expired_on = models.DateTimeField(
          verbose_name=_("An expiration date"),
          help_text=_("An expiration date of collection."),
      )
      query = models.CharField(
          max_length=256,
          verbose_name=_("Query"),
          help_text=_("Query for collection."),
      )
      comment = models.CharField(
          max_length=256,
          blank=True,
          verbose_name=_("Comment"),
          help_text=_("Comment for collection."),
      )
      public = models.BooleanField(
          default=False, verbose_name=_("Public"), help_text=_("Make public.")
      )
  