Fix TypeError in CustomInitCommandSet.do_show_arg* methods

Remove the extra '_cmd' argument from 'do_show_arg1' and 'do_show_arg2'
in 'examples/modular_commands/commandset_custominit.py'. This fixes a
TypeError where the commands expected 3 arguments but were called with 2
during execution.

Author: tleonhardt

examples/modular_commands/commandset_custominit.py

@@ -1,7 +1,6 @@
 """A simple example demonstrating a loadable command set."""
 
 from cmd2 import (
-    Cmd,
     CommandSet,
     Statement,
     with_default_category,
@@ -16,8 +15,8 @@ def __init__(self, arg1, arg2) -> None:
         self._arg1 = arg1
         self._arg2 = arg2
 
-    def do_show_arg1(self, _cmd: Cmd, _: Statement) -> None:
+    def do_show_arg1(self, _: Statement) -> None:
         self._cmd.poutput('Arg1: ' + self._arg1)
 
-    def do_show_arg2(self, _cmd: Cmd, _: Statement) -> None:
+    def do_show_arg2(self, _: Statement) -> None:
         self._cmd.poutput('Arg2: ' + self._arg2)