text: from django.db import models
  from django.contrib import admin
  from django.utils.translation import gettext as _
  
  
  class Graph(models.Model):
      func = models.CharField(verbose_name=_("function"), max_length=255)
      image = models.FilePathField(verbose_name=_("image"), null=True)
      error = models.CharField(verbose_name=_("error"),
                               max_length=511,
                               null=True)
      interval = models.IntegerField(verbose_name=_("interval"), default=7)
      step = models.IntegerField(verbose_name=_("step"), default=2)
      date_created = models.DateTimeField(verbose_name=_("crated"),
                                          auto_now_add=True)
      date_processed = models.DateTimeField(verbose_name=_("processed"),
                                            null=True)
  
      def __str__(self):
          return f"{self.func}, {self.date_processed}"