index.js
function copy (target, source) {
  for (var key in Object(source)) target[key] = source[key]
  return target
}
function copy (target, source) {
  for (var key in Object(source)) target[key] = source[key]
  return target
}
Copy properties from source to target.

@param {Object} target
Object to assign properties to.

@param {Object} source
Object to get properties from.

@return {Object}
New object.