/*
 *  call-seq:
 *     fis << fi -> fis
 *     fis.add(fi) -> fis
 *
 *  Add a FieldInfo object. Use the FieldInfos#add_field method where
 *  possible.
 */
static VALUE
frt_fis_add(VALUE self, VALUE rfi)
{
    FieldInfos *fis = (FieldInfos *)DATA_PTR(self);
    FieldInfo *fi = (FieldInfo *)frt_rb_data_ptr(rfi);
    fis_add_field(fis, fi);
    REF(fi);
    return self;
}