function property(key) {
      return function(object) {
        return object[key];
      };
    }
Creates a "_.pluck" style function, which returns the `key` value of a
given object.

@static
@memberOf _
@category Utilities
@param {string} key The name of the property to retrieve.
@returns {Function} Returns the new function.
@example

var characters = [
  { 'name': 'fred',   'age': 40 },
  { 'name': 'barney', 'age': 36 }
];

var getName = _.property('name');

_.map(characters, getName);
// => ['barney', 'fred']

_.sortBy(characters, getName);
// => [{ 'name': 'barney', 'age': 36 }, { 'name': 'fred',   'age': 40 }]