/*
 *  call-seq:
 *     clause.required? -> bool
 *
 *  Return true if this clause is required. ie, this will be true if occur was
 *  equal to +:must+.
 */
static VALUE
frt_bc_is_required(VALUE self)
{
    GET_BC();
    return bc->is_required ? Qtrue : Qfalse;
}