Preserve explicit parsing on empty responses

Author: Sayan-

src/kernel/_response.py

@@ -16,7 +16,6 @@
     Iterator,
     AsyncIterator,
     cast,
-    get_args,
     overload,
 )
 from typing_extensions import Awaitable, ParamSpec, override, get_origin
@@ -186,7 +185,7 @@ def _parse(self, *, to: type[_T] | None = None) -> R | _T:
             return cast(R, None)
 
         response = self.http_response
-        if response.status_code == 204 and NoneType in get_args(cast_to):
+        if response.status_code == 204 and to is None and is_basemodel(cast_to):
             return cast(R, None)
         if cast_to == str:
             return cast(R, response.text)

src/kernel/resources/browser_pools.py

@@ -607,7 +607,7 @@ def acquire(
             options=make_request_options(
                 extra_headers=extra_headers, extra_query=extra_query, extra_body=extra_body, timeout=timeout
             ),
-            cast_to=Optional[BrowserPoolAcquireResponse],
+            cast_to=BrowserPoolAcquireResponse,
         )
 
     def flush(
@@ -1264,7 +1264,7 @@ async def acquire(
             options=make_request_options(
                 extra_headers=extra_headers, extra_query=extra_query, extra_body=extra_body, timeout=timeout
             ),
-            cast_to=Optional[BrowserPoolAcquireResponse],
+            cast_to=BrowserPoolAcquireResponse,
         )
 
     async def flush(

tests/test_browser_pool_acquire_response.py

@@ -37,6 +37,9 @@ def handle(_request: httpx.Request) -> httpx.Response:
         response = client.browser_pools.with_raw_response.acquire("pool")
         assert response.status_code == 204
         assert response.parse() is None
+        assert response.parse(to=str) == ""
+        assert response.parse(to=bytes) == b""
+        assert response.parse(to=httpx.Response) is response.http_response
         assert calls == 2