How to retrieve the calling User in a custom function without passing it as a parameter ?

After exploring different plugins, it appears that the only context injectable in custom functions is  com.appiancorp.services.ServiceContext.

Since then, it's possible to retrieve the caller like shown in the next reply.

	@Function
	public TypedValue sysInfo(ServiceContext
			  sc,UserProfileService ups_) throws AppianException {
		HashMap<TypedValue, TypedValue> ret = new HashMap<TypedValue, TypedValue>();
		try {
			
			UserProfile profile = ups_.getUser(sc.getName());
			if (!profile.getUserTypeId().equals(UserProfile.USER_TYPE_SYS_ADMIN)) {
				String errorText = "User " + profile.getUsername()
						+ " is not a System Administrator.  You must run sysInfo as an administrator.";
				LOG.error(errorText);
				throw new Exception(errorText);
			}
			
	.....