How to use the pyfcm.baseapi.BaseAPI function in pyfcm

def base_api():
    api_key = os.getenv("FCM_TEST_API_KEY", None)
    assert api_key, "Please set the environment variables for testing according to CONTRIBUTING.rst"

    return BaseAPI(api_key=api_key)

def test_init_baseapi():
    try:
        BaseAPI()
        assert False, "Should raise AuthenticationError"
    except errors.AuthenticationError:
        pass

from .baseapi import BaseAPI
from .errors import InvalidDataError


class FCMNotification(BaseAPI):
    def notify_single_device(self,
                             registration_id=None,
                             message_body=None,
                             message_title=None,
                             message_icon=None,
                             sound=None,
                             condition=None,
                             collapse_key=None,
                             delay_while_idle=False,
                             time_to_live=None,
                             restricted_package_name=None,
                             low_priority=False,
                             dry_run=False,
                             data_message=None,
                             click_action=None,
                             badge=None,

from tornado import escape
from tornado import gen
from tornado.httpclient import AsyncHTTPClient, HTTPRequest

from ..baseapi import BaseAPI
from ..errors import AuthenticationError, InternalPackageError, FCMServerError
from ..fcm import FCMNotification


class TornadoBaseAPI(BaseAPI):
    def __init__(self, *args, **kwargs):
        super(TornadoBaseAPI, self).__init__(*args, **kwargs)
        self.http_client = AsyncHTTPClient()

    @gen.coroutine
    def send_request(self, payloads=None):
        for payload in payloads:
            request = HTTPRequest(
                url=self.FCM_END_POINT,
                method='POST',
                headers=self.request_headers(),
                body=payload
            )

            response = yield self.http_client.fetch(request)