Support for paymentsOnly parameter in Journals endpoint

[jdpanganiban]

I'm trying to pull data from the Journals endpoint on a cash basis, but when I send the request using the following:
xero.journals.filter(paymentsOnly=True)

I get the following error: "QueryParseException: No property or field 'paymentsOnly' exists in type Journal."

Does the filter method support paymentsOnly or is there a different way of pulling journals on a cash basis in the SDK?

Thanks!