Check transport is not closing before writing to it

houdini/spheniscidae.py

@@ -79,6 +79,7 @@ class Spheniscidae:
         await self.send_line(xml_data.decode('utf-8'))
 
     async def send_line(self, data):
+        if not self.__writer.is_closing():
             self.logger.debug(f'Outgoing data: {data}')
             self.__writer.write(data.encode('utf-8') + Spheniscidae.Delimiter)