code: def _validate_collection(self):
          
          if not self._id:
              msg = "No 'id' in Collection for request '{}'"
              raise ValidationError(msg.format(self.url))
  
          if not self._title:
              msg = "No 'title' in Collection for request '{}'"
              raise ValidationError(msg.format(self.url))
  
          if self._can_read is None:
              msg = "No 'can_read' in Collection for request '{}'"
              raise ValidationError(msg.format(self.url))
  
          if self._can_write is None:
              msg = "No 'can_write' in Collection for request '{}'"
              raise ValidationError(msg.format(self.url))
  
          if self._id not in self.url:
              msg = "The collection '{}' does not match the url for queries '{}'"
              raise ValidationError(msg.format(self._id, self.url))
docs: Validates Collection information. Raises errors for required
          properties.