set_category
Description:
Sets the type of this to category
.
Categories have a main type like `email`, `im` or `device` and can have a detail separated by a `.`, e.g. `im.received` or `email.arrived`. Setting the category helps the notification server to select proper feedback to the user.
Standard categories are listed in the specification.
Parameters:
this | |
category |
the category for this, or null for no category |