101 : how do I debug a GST java app with GST_DEBUG="*:3"

[gstream at ccc2.com]

HI all, a basic 101 that I cant seem to figure out. How do I use the
GST_DEBUG="*:3" command. Is it in the cmd line, in the code?? I have been
trying for a few weeks and cant get anything and google is not very
helpful on this?

thx
Art