import static org.junit.jupiter.api.Assertions.assertThrows;

class FileSourceTest {

    @Test
    void testFileSource() {
        NullPointerException e = assertThrows(
                NullPointerException.class,
                () -> new FileSource((File) null),
                "Should fail, since you must specify a file");
        assertEquals("file cannot be null", e.getMessage());
    }

     * @return the derived session
     * @throws NullPointerException if {@code repositories} is null
     */
    @Nonnull
    Session withRemoteRepositories(@Nonnull List<RemoteRepository> repositories);

    /**
     * Register the given listener which will receive all events.
     *
     * @param listener the listener to register
     * @throws NullPointerException if {@code listener} is null
     */

        this.baseFilename = baseFilename;
        this.fileSuffix = fileSuffix;

        initializeCleanupMonitoring();
    }

    private void initializeCleanupMonitoring() {
        callerInfo = new NullPointerException().getStackTrace()[2];

        Runnable warning = this::maybeWarnAboutCleanUp;

        cleanupWarning = new Thread(warning);

        Runtime.getRuntime().addShutdownHook(cleanupWarning);
    }

        assertThrows(
                IllegalArgumentException.class, () -> rtInfo.isMavenVersion(""), "Bad version range wasn't rejected");

        assertThrows(
                NullPointerException.class, () -> rtInfo.isMavenVersion(null), "Bad version range wasn't rejected");
    }

     *         obtained, the returned version range's recommended version is set to <code>null</code>.
     *         </p>
     * @throws NullPointerException if the specified <code>VersionRange</code> is
     *                              <code>null</code>.
     */
    public VersionRange restrict(VersionRange restriction) {

        final ModelResolver modelResolver = getModelResolver(request);
        if (workspaceResolver == null && modelResolver == null) {
            throw new NullPointerException(String.format(
                    "request.workspaceModelResolver and request.modelResolver cannot be null (parent POM %s and POM %s)",