code: function closest (el, sel) {
    if (!el) return
    if (matches(el, sel)) {
      return el
    } else {
      return closest(el.parentNode, sel)
    }
  }
docs: closest : closest(el, selector)
  Looks for the closest ancestor of element `el` that matches `selector`.
  Compare with [$.fn.closest](http://api.jquery.com/closest/).
  
  var closest = require('dom101/closest');
  
  closest(input, 'label');