old_contents: from django.db import models
  from pizzaplace.models import PizzaPlace
  from django.core.validators import RegexValidator
  from meetup.services.meetup_api_lookup_agent import MeetupApiLookupAgent
  from django.core.exceptions import ValidationError
  from model_utils.models import TimeStampedModel
  
  def validate_urlname(link):
    validator = RegexValidator(
      regex='meetup\.com\/\w+(-\w+)*\/$',
      message="Url should be in form 'meetup.com/meetup-name/'",
      code='invalid_url')
    return validator(link)
  
  def validate_meetup_exists(link):
    if not MeetupApiLookupAgent(link).meetup_exists():
      raise ValidationError("Meetup not found on meetup.com")
  
  
  
  
  class Meetup(TimeStampedModel):
    name = models.CharField(max_length=500, null=False, blank=False, default=None, unique=True)
    meetup_link = models.URLField(max_length=500,
                                  unique=True,
                                  default=None,
                                  validators=[validate_urlname, validate_meetup_exists])
    pizza_places = models.ManyToManyField(PizzaPlace)
  
    def __str__(self):
      return self.name
  
  
  
new_contents: from django.db import models
  from pizzaplace.models import PizzaPlace
  from django.core.validators import RegexValidator
  from meetup.services.meetup_api_lookup_agent import MeetupApiLookupAgent
  from django.core.exceptions import ValidationError
  from model_utils.models import TimeStampedModel
  
  def validate_urlname(link):
    validator = RegexValidator(
      regex='meetup\.com\/\w+(-\w+)*\/$',
      message="Url should be in form 'meetup.com/meetup-name/'",
      code='invalid_url')
    return validator(link)
  
  def validate_meetup_exists(link):
    if not MeetupApiLookupAgent(link).meetup_exists():
      raise ValidationError("Meetup not found on meetup.com")
      
  
  class Meetup(TimeStampedModel):
    name = models.CharField(max_length=500, null=False, blank=False, default=None, unique=True)
    meetup_link = models.URLField(max_length=500,
                                  unique=True,
                                  default=None,
                                  validators=[validate_urlname, validate_meetup_exists])
    pizza_places = models.ManyToManyField(PizzaPlace)
  
    def __str__(self):
      return self.name
  
  
  
subject: Remove whitespace