How to use the rdf-ext.parsers function in rdf-ext

$.get(href, function (matchersTtl) {
                        rdf.parsers.parse('text/turtle', matchersTtl, null, window.location.toString().split('#')[0]).then(function (matchers) {
                            console.log(matchers.toString());
                            matchersGraph.addAll(matchers);
                            if (matcherLinks.length > currentLink) {
                                processLink();
                            } else {
                                resolve(matchersGraph);
                            }
                        });
                    });
                };

function parse(serializedRDF, serializationFormat) {
            if (!serializationFormat) {
                serializationFormat = 'text/turtle';
            }
            rdf.parsers.parse(serializationFormat, serializedRDF, null, window.location.toString().split('#')[0]).then(function (matchers) {
                console.log(matchers.toString());
                resolve(matchers);
            });
        }
        var matchersElem = $("#matchers");