function isObject(value) {
  // http://jsperf.com/isobject4
  return value !== null && typeof value === 'object';
}
@ngdoc function
@name angular.isObject
@module ng
@kind function

@description
Determines if a reference is an `Object`. Unlike `typeof` in JavaScript, `null`s are not
considered to be objects. Note that JavaScript arrays are objects.

@param {*} value Reference to check.
@returns {boolean} True if `value` is an `Object` but not `null`.