1. DomName('DOMImplementation.createDocument')
  2. DocsEditable()
XmlDocument createDocument(String namespaceURI, String qualifiedName, _DocumentType doctype)

Source 

@DomName('DOMImplementation.createDocument')
@DocsEditable()
XmlDocument createDocument(String namespaceURI, String qualifiedName, _DocumentType doctype) => _blink.BlinkDOMImplementation.instance.createDocument_Callback_3_(this, namespaceURI, qualifiedName, doctype);