Call the hexists command to check if the redis hash key exists for the
        current field

def hexists(self):
        """
        Call the hexists command to check if the redis hash key exists for the
        current field
        """
        try:
            key = self.key
        except DoesNotExist:
            """
            If the object doesn't exists anymore, its PK is deleted, so the
            "self.key" call will raise a DoesNotExist exception. We catch it
            to return False, as the field doesn't exists too.
            """
            return False
        else:
            return self.connection.hexists(key, self.name)