oorder_record         pending_chain_state::get_short_record( const market_index_key& key )const
 {
    auto rec_itr = shorts.find( key );
    if( rec_itr == shorts.end() ) return rec_itr->second;
    else if( _prev_state ) return _prev_state->get_short_record( key );
    return oorder_record();
 }
oorder_record pending_chain_state::get_short_record( const market_index_key& key )const
{
    chain_interface_ptr prev_state = _prev_state.lock();
    auto rec_itr = shorts.find( key );
    if( rec_itr != shorts.end() ) return rec_itr->second;
    else if( prev_state ) return prev_state->get_short_record( key );
    return oorder_record();
}