index.js
function copy(target, obj) {
  if (isObject(obj)) {
    forIn(obj, function(value, key) {
      target[key] = value;
    });
  }
}
function copy(target, obj) {
  if (isObject(obj)) {
    forIn(obj, function(value, key) {
      target[key] = value;
    });
  }
}
function copy ( target , obj ) { if ( isObject ( obj ) ) { forIn ( obj , function ( value , key ) { target [ key ] = value ; } ) ; } }
copy properties from the source object to the
target object. We don't use `Object.keys` here, since
"mixin" also adds non-enumerable keys.

@param  {*} `value`
@param  {String} `key`
copy properties from the source object to the target object . We don t use Object . keys here since mixin also adds non - enumerable keys .