*/
    @Nullable
    default String interpolate(
            @Nullable String val, @Nullable Function<String, String> callback, boolean defaultsToEmpty) {
        return interpolate(val, callback, null, defaultsToEmpty);
    }

    /**
     * Interpolates a single string value using the provided callback function.
     *
     * @param val The string to be interpolated.

public interface ModelInterpolator {

    /**
     * Interpolates expressions in the specified model. Note that implementations are free to either interpolate the
     * provided model directly or to create a clone of the model and interpolate the clone. Callers should always use
     * the returned model and must not rely on the input model being updated.
     *
     * @param model The model to interpolate, must not be {@code null}.

            for (ValueSource vs : valueSources) {
                interpolator.addValueSource(vs);
            }

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

            try {
                try {
                    result = interpolator.interpolate(result, recursionInterceptor);

            }
        } finally {
            getInterpolator().clearAnswers();
        }
    }

    protected Interpolator createInterpolator() {
        StringSearchInterpolator interpolator = new StringSearchInterpolator();
        interpolator.setCacheAnswers(true);

        return interpolator;
    }

    private static final class InterpolateObjectAction implements PrivilegedAction<ModelInterpolationException> {

                        it.set(interpolator.interpolate(it.next()));
                    }
                }
                commandLineBuilder.addOption(option);
            }
            for (String arg : options.commandLine.getArgList()) {
                commandLineBuilder.addArg(interpolator.interpolate(arg));
            }
            return new CommonsCliEncryptOptions(

                    fileString = interpolator.interpolate(fileString, "").replace("\\", "/");
                    File file = new File(fileString);
                    return !file.exists();
                }
            } catch (InterpolationException e) {
                if (logger.isDebugEnabled()) {
                    logger.debug("Failed to interpolate missing file location for profile activator: " + fileString, e);
                } else {

            }
        });

        interpolator.addValueSource(new MapBasedValueSource(context.getProjectProperties()));

        interpolator.addValueSource(new MapBasedValueSource(context.getUserProperties()));

        interpolator.addValueSource(new MapBasedValueSource(context.getSystemProperties()));

        String absolutePath = interpolator.interpolate(path, "");

        final StringSearchInterpolator interpolator = new StringSearchInterpolator();
        interpolator.setCacheAnswers(true);
        for (ValueSource vs : valueSources) {
            interpolator.addValueSource(vs);
        }
        for (InterpolationPostProcessor postProcessor : postProcessors) {
            interpolator.addPostProcessor(postProcessor);
        }

    /**
     * @deprecated Use {@link ModelInterpolator#interpolate(Model, File, ProjectBuilderConfiguration, boolean)} instead.
     */
    @Deprecated
    Model interpolate(Model project, Map<String, ?> context) throws ModelInterpolationException;

    /**
     * @deprecated Use {@link ModelInterpolator#interpolate(Model, File, ProjectBuilderConfiguration, boolean)} instead.
     */
    @Deprecated

                        it.set(interpolator.interpolate(it.next()));
                    }
                }
                commandLineBuilder.addOption(option);
            }
            for (String arg : options.commandLine.getArgList()) {
                commandLineBuilder.addArg(interpolator.interpolate(arg));
            }
            return new CommonsCliMavenOptions(