feat(MyPy): Endpoint annontations

sinch/core/endpoint.py

@@ -1,17 +1,23 @@
 from abc import ABC, abstractmethod
 from sinch.core.models.http_response import HTTPResponse
+from sinch.core.models.http_request import HttpRequest
+from sinch.core.models.base_model import SinchBaseModel
 from sinch.core.enums import HTTPAuthentication, HTTPMethod
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from sinch.core.clients.sinch_client_base import ClientBase
 
 
 class HTTPEndpoint(ABC):
     ENDPOINT_URL: str
     HTTP_METHOD: HTTPMethod
     HTTP_AUTHENTICATION: HTTPAuthentication
 
-    def __init__(self, project_id, request_data):
+    def __init__(self, project_id: str, request_data: 'HttpRequest'):
         pass
 
-    def build_url(self, sinch) -> str:
+    def build_url(self, sinch: 'ClientBase') -> str:
         return ''
 
     def build_query_params(self) -> dict:
@@ -21,5 +27,5 @@ def request_body(self) -> dict:
         return {}
 
     @abstractmethod
-    def handle_response(self, response: HTTPResponse):
+    def handle_response(self, response: HTTPResponse) -> SinchBaseModel:
         pass