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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _post_login_page(self):
 """Login to Janrain."""

        # Prepare post data
        data = {
            "form": "signInForm",
            "client_id": JANRAIN_CLIENT_ID,
            "redirect_uri": "https://www.fido.ca/pages/#/",
            "response_type": "token",
            "locale": "en-US",
            "userID": self.username,
            "currentPassword": self.password,
        }
        # HTTP request
        try:
            raw_res = yield from self._session.post(LOGIN_URL,
                                                    headers=self._headers,
                                                    data=data,
                                                    timeout=self._timeout)
        except OSError:
            raise PyFidoError("Can not sign in")

        return True