public MetricRegistrationBuilder addNamePart(final String namePart) {
        if (nameParts == null) {
            nameParts = new ArrayList<>();
        }

        if (NullSafe.isNonBlankString(namePart)) {
            nameParts.add(namePart);
        }
        return this;
    }
Adds a name part. Each part will have unsuitable characters stripped and be separated
by a '.' character. Name parts will be appended onto the fully qualified class name.
stroom-util/src/main/java/stroom/util/metrics/MetricRegistrationBuilder.java