index.js
function _start() {
    var now = Date.now();
    var config = this._config;

    var missing = !config ? required : required.filter(function(key) {
      return config[key] === undefined;
    });

    if (missing.length) {
      throw TypeError('Missing config properties: ' + missing.join(', '));
    }

    if (this._started) {
      throw Error('Ticker already started');
    }

    this._started = now;
    this._before = now - config.delay;

    this._tick();

    return this;
  }
function _start() {
    var now = Date.now();
    var config = this._config;

    var missing = !config ? required : required.filter(function(key) {
      return config[key] === undefined;
    });

    if (missing.length) {
      throw TypeError('Missing config properties: ' + missing.join(', '));
    }

    if (this._started) {
      throw Error('Ticker already started');
    }

    this._started = now;
    this._before = now - config.delay;

    this._tick();

    return this;
  }
function _start ( ) { var now = Date . now ( ) ; var config = this . _config ; var missing = ! config ? required : required . filter ( function ( key ) { return config [ key ] === undefined ; } ) ; if ( missing . length ) { throw TypeError ( 'Missing config properties: ' + missing . join ( ', ' ) ) ; } if ( this . _started ) { throw Error ( 'Ticker already started' ) ; } this . _started = now ; this . _before = now - config . delay ; this . _tick ( ) ; return this ; }
Used with config.limit 
Start the ticker, setting the timeout for the first tick.
@returns {Ticker}
Used with config . limit Start the ticker setting the timeout for the first tick .