oproposal_vote        pending_chain_state::get_proposal_vote( proposal_vote_id_type id )const
 {
    auto rec_itr = proposal_votes.find(id);
    if( rec_itr != proposal_votes.end() ) return rec_itr->second;
    else if( _prev_state ) return _prev_state->get_proposal_vote( id );
    return oproposal_vote();
 }
oproposal_vote pending_chain_state::get_proposal_vote( proposal_vote_id_type id )const
{
    chain_interface_ptr prev_state = _prev_state.lock();
    auto rec_itr = proposal_votes.find(id);
    if( rec_itr != proposal_votes.end() ) return rec_itr->second;
    else if( prev_state ) return prev_state->get_proposal_vote( id );
    return oproposal_vote();
}