<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _verify_credentials(self):
 """ An internal method that verifies the credentials given at instantiation. :raises: :class:`Pymoe.errors.UserLoginFailed` """

        r = requests.get(self.apiurl + "account/verify_credentials.xml",
                         auth=HTTPBasicAuth(self._username, self._password),
                         headers=self.header)
        if r.status_code != 200:
            raise UserLoginFailed("Username or Password incorrect.")