RegexBasedInterpolator interpolator = new RegexBasedInterpolator();
            try {
                interpolator.addValueSource(new EnvarBasedValueSource());
            } catch (IOException e) {
                // ignored
            }
            interpolator.addValueSource(new MapBasedValueSource(System.getProperties()));

            try {
                if (fileString != null && !fileString.isEmpty()) {

        }

        Logger logger = getLogger();

        String result = src;
        synchronized (this) {
            for (ValueSource vs : valueSources) {
                interpolator.addValueSource(vs);
            }

            for (InterpolationPostProcessor postProcessor : postProcessors) {
                interpolator.addPostProcessor(postProcessor);
            }

            try {