*/
    @Nonnull
    Map<String, String> getSystemProperties();

    /**
     * Each invocation computes a new map of effective properties. To be used in interpolation.
     * <p>
     * Effective properties are computed from system, user and optionally project properties, layered with
     * defined precedence onto each other to achieve proper precedence. Precedence is defined as:
     * <ul>

import org.eclipse.aether.util.repository.SimpleArtifactDescriptorPolicy;

import static java.util.Objects.requireNonNull;

/**
 * A simple {@link Supplier} of {@link SessionBuilder} instances, that on each call supplies newly
 * constructed instance. To create session out of builder, use {@link SessionBuilder#build()}. For proper closing
 * of sessions, use {@link CloseableSession#close()} method on built instance(s).
 * <p>

     * configuration expansion (merging configuration defined globally for a given plugin
     * using {@link org.apache.maven.api.model.Plugin#getConfiguration()}
     * into the configuration for each {@link org.apache.maven.api.model.PluginExecution}.
     */
    boolean isProcessPlugins();

    /**
     * Defines external profiles that may be activated for the given model.

      <url>http://svn.apache.org/maven-snapshot-repository</url>
      <releases>
        <enabled>false</enabled>
      </releases>
    </repository>
  </repositories>
  <distributionManagement>
    <!-- Site omitted - each project must provide their own -->
    <repository>
      <id>apache.releases</id>
      <name>Apache Release Distribution Repository</name>
      <url>scp://minotaur.apache.org/www/www.apache.org/dist/maven-repository</url>

import org.eclipse.aether.version.VersionScheme;

/**
 * A simple memorizing {@link Supplier} of {@link RepositorySystem} instance, that on first call
 * supplies lazily constructed instance, and on each subsequent call same instance. Hence, this instance should be
 * thrown away immediately once repository system was created and there is no need for more instances. If new