private void unexpectedError(final String method, final Throwable t) {
        String message = "";
        if (t != null) {
            if (t.getMessage() != null) {
                message = t.getMessage();
            }
            if (message == null || message.trim().isEmpty()) {
                message = t.getClass().getName();
            }
        }

        errorReceiverProxy.log(Severity.ERROR, null, getElementId(),
                "Unexpected error thrown by schema validator in method " + method + ": " + message, t);
    }
Not implemented.

@return null.
@see org.xml.sax.Locator#getSystemId()
stroom-pipeline/src/main/java/stroom/pipeline/filter/SchemaFilter.java