docs: function _resolve(from, to) {
  	if (typeof to === 'undefined') {
  		to = from;
  		from = void(0);
  	}
  
  	if (!path.extname(to)) {
  		to += '.js';
  	}
  
  	return (typeof from === 'undefined') ? path.resolve(to) : path.resolve(from, to);
  }