module_name is part of the command interface for april library.

p.list

Usage

p.list	lists the plug-ins and their paths
p.list help	prints usage instructions

p.load <file-name>	loads specified plug-in file
p.load help	prints usage instructions

p.unload <index>	unloads the plug-in at specified index
p.unload <name>	unloads the plug-in having that name
p.unload help	prints usage instructions