Use assert instead of raise AssertionError

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

Author: llucax

src/frequenz/sdk/microgrid/connection_manager.py

@@ -172,16 +172,12 @@ async def initialize(server_url: str) -> None:
             where the port should be an int between `0` and `65535` (defaulting to
             `9090`) and ssl should be a boolean (defaulting to false). For example:
             `grpc://localhost:1090?ssl=true`.
-
-    Raises:
-        AssertionError: If method was called more then once.
     """
     # From Doc: pylint just try to discourage this usage.
     # That doesn't mean you cannot use it.
     global _CONNECTION_MANAGER  # pylint: disable=global-statement
 
-    if _CONNECTION_MANAGER is not None:
-        raise AssertionError("MicrogridApi was already initialized.")
+    assert _CONNECTION_MANAGER is None, "MicrogridApi was already initialized."
 
     _logger.info("Connecting to microgrid at %s", server_url)
 
@@ -190,8 +186,7 @@ async def initialize(server_url: str) -> None:
 
     # Check again that _MICROGRID_API is None in case somebody had the great idea of
     # calling initialize() twice and in parallel.
-    if _CONNECTION_MANAGER is not None:
-        raise AssertionError("MicrogridApi was already initialized.")
+    assert _CONNECTION_MANAGER is None, "MicrogridApi was already initialized."
 
     _CONNECTION_MANAGER = microgrid_api