Test that the parameters to DOMImplementation.createDocumentType() are mandatory and non-nullable On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE". PASS document.implementation.createDocumentType() threw exception TypeError: Not enough arguments. PASS document.implementation.createDocumentType('a') threw exception TypeError: Not enough arguments. PASS document.implementation.createDocumentType('a', '') threw exception TypeError: Not enough arguments. PASS docType = document.implementation.createDocumentType(null, null, null) did not throw exception. PASS docType.name is "null" PASS docType.nodeName is "null" PASS docType.publicId is "null" PASS docType.systemId is "null" PASS successfullyParsed is true TEST COMPLETE