text: from django.db import models
  from django.contrib.postgres import fields
  
  
  class Conference(models.Model):
      source = models.CharField(max_length=32)
      title = models.CharField(max_length=255)
      url = models.URLField(null=True, blank=True)
      slug = models.CharField(max_length=128, db_index=True)
      year = models.IntegerField(null=True, blank=True)
      key_dates = fields.JSONField(default=dict, null=True, blank=True)
      start_date = models.DateField(null=True, blank=True)
      end_date = models.DateField(null=True, blank=True)
      description = models.TextField(null=True, blank=True)
      key_words = fields.ArrayField(models.CharField(max_length=256), null=True, blank=True)
      x_coord = models.FloatField()
      y_coord = models.FloatField()
      degree = models.PositiveSmallIntegerField()
  
  
  class ConferenceGraphEdge(models.Model):
      conf_1 = models.CharField(max_length=128, db_index=True)
      conf_2 = models.CharField(max_length=128, db_index=True)
      matches_len = models.PositiveSmallIntegerField()
      matches = models.CharField(max_length=512)
      source = models.CharField(max_length=32)
  