How to use sgtk.platform.create_engine_launcher to get the paths to DCCs?

I’m trying to get the tk-maya launcher so that I might be able to get the software path using the toolkit, but I get the following error:

TankLoadPluginError: Error loading the file ‘C:\Users\jaira\AppData\Roaming\Shotgun\bundle_cache\app_store\tk-maya\v0.10.1\startup.py’. Couldn’t find a single class deriving from ‘SoftwareLauncher’. You need to have exactly one class defined in the file deriving from that base class. If your file looks fine, it is possible that the cached .pyc file that python generates is invalid and this is causing the error. In that case, please delete the .pyc file and try again.

This is the code I’m using:
TankLoadPluginError: Error loading the file ‘C:\Users\jaira\AppData\Roaming\Shotgun\bundle_cache\app_store\tk-maya\v0.10.1\startup.py’. Couldn’t find a single class deriving from ‘SoftwareLauncher’. You need to have exactly one class defined in the file deriving from that base class. If your file looks fine, it is possible that the cached .pyc file that python generates is invalid and this is causing the error. In that case, please delete the .pyc file and try again.

launcher = sgtk.platform.create_engine_launcher(
tk=self.engine.sgtk,
context=self.engine.sgtk.context_from_path(
self.config[‘shotgun’][‘root’]
),
engine_name=‘tk-maya’
)
software_versions = launcher.scan_software()

I have followed the instructions from the bootstrap API documentation and bootstrapped an engine called tk-shell. But wondering why this error occurs, how can I get the launcher for Maya, or maybe there is a better solution to get those paths.