*/
    protected void pushUserProperties(C context) throws Exception {
        ProtoSession protoSession = context.protoSession;
        HashSet<String> sys = new HashSet<>(protoSession.getSystemProperties().keySet());
        if (context.pushedUserProperties == null) {
            context.pushedUserProperties = new HashSet<>();
            protoSession.getUserProperties().entrySet().stream()

                        "The specified user toolchains file does not exist: " + userToolchainsFile);
            }
        } else {
            String userToolchainsFileStr =
                    context.protoSession.getEffectiveProperties().get(Constants.MAVEN_USER_TOOLCHAINS);
            if (userToolchainsFileStr != null) {
                userToolchainsFile = context.cwd.resolve(userToolchainsFileStr);
            }
        }

import org.apache.maven.api.toolchain.ToolchainModel;

/**
 * The session to install / deploy / resolve artifacts and dependencies.
 *
 * @since 4.0.0
 */
@Experimental
@ThreadSafe
public interface Session extends ProtoSession {

    /**
     * Returns the current maven version.
     *
     * @return the maven version, never {@code null}
     */
    @Nonnull
    Version getMavenVersion();

    /**