lib/extract.js
function extractValue(attr, node) {
                    if (attr === 'translate') {
                        return node.html() || getAttr(attr) || '';
                    }
                    return getAttr(attr) || node.html() || '';
                }
function extractValue(attr, node) {
                    if (attr === 'translate') {
                        return node.html() || getAttr(attr) || '';
                    }
                    return getAttr(attr) || node.html() || '';
                }
Extract the value, default translate filter behavior
else if it is an attribute we need to get its value first
@param  {String} attr Key name
@param  {Node} node
@return {String}