/*
 * call-seq: remember(object)
 *
 * Remember _object_, to find out if it was already encountered (if a cyclic
 * data structure is rendered). 
 */
static VALUE cState_remember(VALUE self, VALUE object)
{
    GET_STATE(self);
    return rb_hash_aset(state->seen, rb_obj_id(object), Qtrue);
}