Returns the first_name plus the last_name, with a space in between.

def get_full_name(self):
        """
        Returns the first_name plus the last_name, with a space in between.
        """
        full_name = '{first_name} {last_name}'.format(first_name=self.first_name, last_name=self.last_name)
        return full_name.strip()