/**
     * Gets the system properties to use for interpolation and profile activation. The system properties are collected
     * from the runtime environment like {@link System#getProperties()} and environment variables.
     *
     * @return The execution properties, never {@code null}.
     */
    Map<String, String> getSystemProperties();

    /**

    private final MavenBuildTimestamp mavenBuildTimestamp;

    BuildTimestampValueSource(Date startTime, Properties properties) {
        super(false);
        this.mavenBuildTimestamp = new MavenBuildTimestamp(startTime, properties);
    }

    @Override
    public Object getValue(String expression) {
        if ("build.timestamp".equals(expression) || "maven.build.timestamp".equals(expression)) {

    /**
     * Gets the system properties to use for interpolation and profile activation. The system properties are collected
     * from the runtime environment like {@link System#getProperties()} and environment variables.
     *
     * @return The system properties, never {@code null}.
     */
    Properties getSystemProperties();

    /**

    MavenExecutionRequest setSystemProperties(Properties systemProperties);

    /**
     * Gets the system properties to use for interpolation and profile activation. The system properties are collected
     * from the runtime environment like {@link System#getProperties()} and environment variables.
     *
     * @return The system properties, never {@code null}.
     */
    Properties getSystemProperties();

    /**

        MemberType.FIELD -> hasPropertyAttribute(kmClass::properties, jvmSignature, predicate)
        MemberType.CONSTRUCTOR -> hasConstructorAttribute(kmClass::constructors, jvmSignature, predicate)
        MemberType.METHOD -> hasFunctionAttribute(kmClass::functions, jvmSignature, predicate) ||
            hasPropertyAttribute(kmClass::properties, jvmSignature, predicate)
    }
}


private

 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.model.interpolation;

import java.util.Properties;

import org.apache.maven.model.building.ModelBuildingRequest;

/**
 * Allows a fixed set of properties that are valid inside a version and that could be overwritten for example on the
 * commandline
 *

                    "type": "object",
                    "properties": {"message": {"title": "Message", "type": "string"}},
                },
                "ValidationError": {
                    "title": "ValidationError",
                    "required": ["loc", "msg", "type"],
                    "type": "object",
                    "properties": {
                        "loc": {

        }

        return this;
    }

    @Override
    public Properties getUserProperties() {
        return userProperties;
    }

    @Override
    public ProjectBuildingRequest setUserProperties(Properties userProperties) {
        if (userProperties != null) {
            this.userProperties = new Properties();
            this.userProperties.putAll(userProperties);
        } else {

            "schemas": {
                "Item": {
                    "title": "Item",
                    "required": ["name", "price"],
                    "type": "object",
                    "properties": {
                        "name": {"title": "Name", "type": "string"},
                        "description": {
                            "title": "Description",

    }

    /**
     * Returns a map of user-defined properties for the Maven execution.
     * These properties can be set using the -D command-line option.
     *
     * @return an unmodifiable map of user properties
     */
    @Nonnull
    Map<String, String> userProperties();

    /**
     * Returns a map of system properties for the Maven execution.