return getProperties().elements();
    }

    @Override
    public Set<java.util.Map.Entry<Object, Object>> entrySet() {
        return getProperties().entrySet();
    }

    @Override
    public boolean equals(final Object o) {
        return getProperties().equals(o);
    }

    @Override
    public Object get(final Object key) {
        return getProperties().get(key);
    }

        public String getClassifier() {
            return type.getClassifier() == null ? "" : type.getClassifier();
        }

        @Override
        public Map<String, String> getProperties() {
            return type.getProperties();
        }
    }

                        Map<String, String> props = new HashMap<>(artifact.getProperties());
                        ArtifactType derived = derive(parentType, currentType);
                        props.putAll(derived.getProperties());
                        node.setArtifact(artifact.setProperties(props));
                    }
                }
            }
            stack.push(currentType);

        Properties properties = getMavenProject(project).getProperties();
        if (value == null) {
            properties.remove(key);
        } else {
            properties.setProperty(key, value);
        }
    }

    @Override
    @Nonnull
    public Map<String, String> getProperties(@Nonnull Project project) {
        return Collections.unmodifiableMap(

     *
     * @param annotation the annotation (must not be {@literal null})
     * @return a {@link Map} of annotation element names and values
     */
    public static Map<String, Object> getProperties(final Annotation annotation) {
        assertArgumentNotNull("annotation", annotation);

        final Map<String, Object> map = newHashMap();

    Map<String, String> getUserProperties();

    /**
     * Returns immutable system properties to use for interpolation. The system properties are collected from the
     * runtime environment such as {@link System#getProperties()} and environment variables
     * (prefixed with {@code env.}).
     *
     * @return the system properties, never {@code null}
     */
    @Nonnull
    Map<String, String> getSystemProperties();

    /**

        return request.getProfiles().stream()
                .filter(profile -> activeProfileId.contains(profile.getId()))
                .map(ModelBase::getProperties)
                .flatMap(properties -> properties.entrySet().stream())
                .filter(e -> e.getValue() != null)
                .collect(Collectors.toMap(

     *
     * @param path
     *            The path to the properties file. Must not be {@literal null} or empty string.
     * @return The properties file.
     */
    public static Properties getProperties(final String path) {
        assertArgumentNotEmpty("path", path);

        final Properties props = new Properties();
        final InputStream is = getResourceAsStream(path);
        try {

            if (sourceDominant) {
                merged.putAll(target.getProperties());
                putAll(merged, source.getProperties(), CHILD_DIRECTORY_PROPERTY);
            } else {
                putAll(merged, source.getProperties(), CHILD_DIRECTORY_PROPERTY);
                merged.putAll(target.getProperties());
            }
            target.setProperties(merged);
            target.setLocation(

        model.addProperty("key1", "value1");
        model.addProperty("key2", "value2");
        assertEquals(2, model.getProperties().size());

        // This should not throw NullPointerException
        model.getProperties().clear();
        assertEquals(0, model.getProperties().size());
    }