appname() = atom()
calls() = info
| prep_config_change
| which_applications
| {config_change |
control_application |
load_application |
start_type |
stop_application |
unload_application,
term()}
| {change_application_data, term(), term()}
| {permit_application,
atom() | {application, atom(), term()},
term()}
| {start_application, term(), term()}
| {unset_env, term(), term(), term()}
| {set_env, term(), term(), term(), term()}
state() = #state{}