Make the message argument to send() positional-only

Signed-off-by: Leandro Lucarella <[email protected]>

Author: llucax

src/frequenz/channels/_anycast.py

@@ -318,7 +318,7 @@ def __init__(self, channel: Anycast[_T], /) -> None:
         self._channel: Anycast[_T] = channel
         """The channel that this sender belongs to."""
 
-    async def send(self, message: _T) -> None:
+    async def send(self, message: _T, /) -> None:
         """Send a message across the channel.
 
         To send, this method inserts the message into the Anycast channel's

src/frequenz/channels/_broadcast.py

@@ -317,7 +317,7 @@ def __init__(self, channel: Broadcast[_T], /) -> None:
         self._channel: Broadcast[_T] = channel
         """The broadcast channel this sender belongs to."""
 
-    async def send(self, message: _T) -> None:
+    async def send(self, message: _T, /) -> None:
         """Send a message to all broadcast receivers.
 
         Args:

src/frequenz/channels/_sender.py

@@ -61,7 +61,7 @@ class Sender(ABC, Generic[_T_contra]):
     """An endpoint to sends messages."""
 
     @abstractmethod
-    async def send(self, message: _T_contra) -> None:
+    async def send(self, message: _T_contra, /) -> None:
         """Send a message.
 
         Args: