Maya에서 툴킷 앱 실행을 위한 쉘프 버튼을 추가하려면 어떻게 해야 합니까?

import maya.cmds as cmds

# Define the name of the app command we want to run.
# If your not sure on the actual name you can print the current_engine.commands to get a full list, see below.
tk_app = "Publish..."

try:
    import sgtk

    # get the current engine (e.g. tk-maya)
    current_engine = sgtk.platform.current_engine()
    if not current_engine:
        cmds.error("ShotGrid integration is not available!")

    # find the current instance of the app.
    # You can print current_engine.commands to list all available commands.
    command = current_engine.commands.get(tk_app)
    if not app:
        cmds.error("The Toolkit app '%s' is not available!" % tk_app)

    # now we have the command we need to call the registered callback
    command['callback']()

except Exception, e:
    msg = "Unable to launch Toolkit app '%s': %s" % (tk_app, e)
    cmds.confirmDialog(title="Toolkit Error", icon="critical", message=msg)
    cmds.error(msg)