var deepPick = require('deep-pick');
var objA = {"a": {"z": {}}, "baz": 'baz'};
var objB = {"a": {"z": 99}, "baz": 'baz'};

console.log(deepPick(objA, 'z')); //{ z: {} }
console.log(deepPick(objB, 'z')); //{}

    if (isObject(value)) {
      if (value.hasOwnProperty(prop) && isObject(value[prop])) {
        mixinDeep(acc, value);
      }
      //well my value is object and contains the property but the value[prop] is not object so what now?
    } else {
      acc[key] = value;
    }