code: function( target, attr ) {
      if ( typeof attr !== 'object' )  return
      var len = attr.length
  
      // Native `NamedNodeMap``:
      if (
        typeof attr[0] === 'object' &&
        'name' in attr[0]
      ) {
        for ( var i = 0; i < len; i++ ) {
          if ( attr[ i ].value !== undefined ) {
            target.setAttribute( attr[ i ].name, attr[ i ].value )
          }
        }
  
      // Plain object:
      } else {
        for ( var name in attr ) {
          if (
            attr.hasOwnProperty( name ) &&
            attr[ name ] !== undefined
          ) {
            target.setAttribute( name, attr[ name ] )
          }
        }
      }
      return target
    }
docs: Set attributes all in once with an object.