/*
 *   call-seq:
 *      context.thnum -> int
 *
 *   Returns the context's number.
 */
static VALUE
context_thnum(VALUE self)
{
    debug_context_t *debug_context;

    Data_Get_Struct(self, debug_context_t, debug_context);
    return INT2FIX(debug_context->thnum);
}