P2JS

this.p2world.on('impact', function(evt){
    var bodyA = evt.bodyA,
        bodyB = evt.bodyB;
    if(bodyA.hasOwnProperty('playerId')){
        console.log('bodyA is the player! ', bodyA.playerId);
        var currentPlayer = this.state.players[client.sessionId];
        bodyA.velocity = [0,0];
    } else {
        if(bodyB.hasOwnProperty('playerId')){
            console.log('bodyB is the player! ', bodyB.playerId);
            var currentPlayer = this.state.players[client.sessionId];
            bodyB.velocity = [0,0];
        } else {
            console.log('who the fuck is moving???');
        }
    }
    console.log('bodies position: ', bodyA.position, bodyB.position);
});