<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def init_session(self):
 """ Defines a session object for passing requests. """

        if self.session:
            self.session.close()
        self.session = make_session(self.username,
                                    self.password,
                                    self.bearer_token,
                                    self.extra_headers_dict)