/**
* Declares a namespace. A namespace is undeclared if the {@code uri} is an empty string. The
* default element namespaces is set if the {@code prefix} is empty.
*
* @param prefix namespace prefix
* @param uri namespace uri
* @return self reference
* @throws QueryException query exception
*/
public QueryProcessor namespace(final String prefix, final String uri) throws QueryException {
sc.namespace(prefix, uri);
return this;
}
