Update stream.py

Author: Harshal96

src/h2/stream.py

@@ -1364,24 +1364,26 @@ def _initialize_content_length(self, headers: Iterable[Header]) -> None:
             self._expected_content_length = 0
             return
 
-        content_lengths = []
+        content_length = None
 
         for n, v in headers:
             if n == b"content-length":
                 try:
-                    content_lengths.append(int(v, 10))
+                    parsed_content_length = int(v, 10)
                 except ValueError as err:
                     msg = f"Invalid content-length header: {v!r}"
                     raise ProtocolError(msg) from err
 
-        if not content_lengths:
-            return
+                if content_length is None:
+                    content_length = parsed_content_length
+                elif parsed_content_length != content_length:
+                    msg = "Conflicting content-length headers"
+                    raise ProtocolError(msg)
 
-        if len(set(content_lengths)) != 1:
-            msg = "Conflicting content-length headers"
-            raise ProtocolError(msg)
+        if content_length is None:
+            return
 
-        self._expected_content_length = content_lengths[0]
+        self._expected_content_length = content_length
 
     def _track_content_length(self, length: int, end_stream: bool) -> None:
         """