Said other post: http://portal.ptcuser.org/p/fo/st/topic=16&post=93253#p93253
My final code turned out a little different than the referenced post.
wt.workflow.engine.WfProcess wfprocess = (((wt.workflow.work.WfAssignedActivity)self.getObject()).getParentProcess());
while (roles.hasMoreElements())
wt.project.Role role = (wt.project.Role)roles.nextElement();
if (participants.hasMoreElements())
if (role.getDisplay().equalsIgnoreCase("Assignee")) provider=true;
}
{
throw exp;