@Override
    public void log(final Severity severity, final Location location, final String elementId, final String message) {
        final StoredError error = new StoredError(severity, location, elementId, message);
        if (errors.size() < 100) {
            errors.add(error);
        }
    }
@param ch     the characters from the XML document
@param start  the start position in the array
@param length the number of characters to read from the array
stroom-headless/src/main/java/stroom/headless/HeadlessFilter.java