const params = {witnesses: witnesses};client.api.getParentsAndLastBallAndWitnessListUnit(params, function(err, result) {console.log(result);});
{parent_units: ['OLlkgxuJhX0Ls/G6ElIWF/VhUXOUiHr2xaS0K/pdQmc='],last_stable_mc_ball: '6vMXOW9f0dYP5/ZZRV/oevXfCyYvqeDkEIUQr32nNqQ=',last_stable_mc_ball_unit: 'aTOhoJOU8i326uEb7WJ0NOUuTkP5GMnpf8E0L7qzRIY=',last_stable_mc_ball_mci: 2871211,witness_list_unit: 'oj8yEksX9Ubq7lLc+p6F2uyHUuynugeVq4+ikT67X6E='}