Soap Xml to object conversion getting failed

I need to consume a SOAP web service which has to be converted into JSON.

var xmlData = '<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  xmlns:tns="http://www.Dummy.com" xmlns:n="http://www.Dummy.com/Name/Types"><soap:Header></soap:Header><soap:Body><n:DummyRequest xmlns:n="http://www.Dummy.com/Name/Types" xmlns="http://www.Dummy.com/Name/Types"><n:DummyField1>Humpty</n:DummyField1><n:DummyFilter><c:DummyFilterString xmlns:c="http://www.Dummy.com/Common/Types">Dumpty</c:DummyFilterString></n:DummyFilter><n:DummyAccount><n:DummyName>Dummy</n:DummyName><n:DummyPassword>1234</n:DummyPassword></n:DummyAccount></n:DummyRequest></soap:Body></soap:Envelope>'

Using node-soap module, not able to convert xml to json xmlToObject function. I am getting error as.

TypeError: Cannot read property 'object' of undefined

Any help on this will be really helpful.