$(event.target).closest(Selector.BUTTON)[0]\n    $(button).toggleClass(ClassName.FOCUS, /^focus(in)?$/.test(event.type))\n  })\n\n$(window).on(Event.LOAD_DATA_API, () => {\n  // ensure correct active class is set to match the controls' actual values/states\n\n  // find all checkboxes/readio buttons inside data-toggle groups\n  let buttons = [].slice.call(document.querySelectorAll(Selector.DATA_TOGGLES_BUTTONS))\n  for (let i = 0, len = buttons.length; i < len; i++) {\n    const button = buttons[i]\n...

An implementation may require that all source files for a package inhabit the same directory.
</p>

<h3 id="Import_declarations">Import declarations</h3>

<p>
An import declaration states that the source file containing the declaration
depends on functionality of the <i>imported</i> package
(<a href="#Program_initialization_and_execution">§Program initialization and execution</a>)