/*
 *  call-seq:
 *     lazy_doc.fields -> array of available fields
 *
 *  Returns the list of fields stored for this particular document. If you try
 *  to access any of these fields in the document the field will be loaded.
 *  Try to access any other field an nil will be returned.
 */
static VALUE
frt_lzd_fields(VALUE self)
{
    return rb_ivar_get(self, id_fields);
}