Bundle/WidgetBundle/Twig/LinkExtension.php
protected function addAttr($label, $value, &$attr)
    {
        if (!isset($attr[$label])) {
            $attr[$label] = '';
        } else {
            $attr[$label] .= ' ';
        }
        $attr[$label] .= $value;

        return $this;
    }
protected function addAttr($label, $value, &$attr)
    {
        if (!isset($attr[$label])) {
            $attr[$label] = '';
        } else {
            $attr[$label] .= ' ';
        }
        $attr[$label] .= $value;

        return $this;
    }
protected function addAttr ( $ label , $ value , & $ attr ) { if ( ! isset ( $ attr [ $ label ] ) ) { $ attr [ $ label ] = '' ; } else { $ attr [ $ label ] .= ' ' ; } $ attr [ $ label ] .= $ value ; return $ this ; }
Add a given attribute to given attributes.

@param string $label
@param string $value
@param array  $attr  The current attributes array

@return LinkExtension
Add a given attribute to given attributes .