title: How to override the default value of a Model Field from an Abstract Base Class
body: <p>I've got some code that looks like this:</p>
  
  <pre><code>class BaseMessage(models.Model):
      is_public = models.BooleanField(default=False)
      # some more fields...
  
      class Meta:
          abstract = True
  
  class Message(BaseMessage):
      # some fields...
  </code></pre>
  
  <p>and I'd like to override the default value of the <code>is_public</code> field in the Message model so that it's <code>True</code> for that model.</p>
  
  <p>I've looked through some relevant Django docs and poked around the model objects but I'm having trouble finding the right place to do this. Any suggestions?</p>