The master-lfun query_player_level() is called to verify the usage of this efun.
object obj;
string prefix;
obj = find_player("deepthought");
prefix = file_name(obj);
prefix = prefix[1..strlen(prefix)-1]; /* cut off the leading "/" */
traceprefix(prefix);
/* From here on, only code in the object "std/player#69"
* will be traced.
*/
trace(1|2|4|8);
...
trace(0);