1  var before = require('./before');
 2  
 3  /**
 4   * Creates a function that is restricted to invoking `func` once. Repeat calls
 5   * to the function return the value of the first invocation. The `func` is
 6   * invoked with the `this` binding and arguments of the created function.
 7   *
 8   * @static
 9   * @memberOf _
10   * @since 0.1.0
11   * @category Function
12   * @param {Function} func The function to restrict.
13   * @returns {Function} Returns the new restricted function.
14   * @example
15   *
16   * var initialize = _.once(createApplication);
17   * initialize();
18   * initialize();
19   * // => `createApplication` is invoked once
20   */
21  function once(func) {
22    return before(2, func);
23  }
24  
25  module.exports = once;