*            <code>null</code>.
     * @param parent The (read-only) parent model from which to inherit the values, may be <code>null</code>.
     * @param request The model building request that holds further settings, must not be {@code null}.
     * @param problems The container used to collect problems that were encountered, must not be {@code null}.
     */

     *
     * @param context
     *            The context in which to parse the spec. Must not be {@literal null}.
     * @param spec
     *            A string to be parsed as a <code>URL</code>. Must not be {@literal null} or empty.
     * @return A <code>URL</code>.
     */
    public static URL create(final URL context, final String spec) {

@Deprecated(since = "4.0.0")
public interface ToolchainManagerPrivate {

    /**
     * Retrieves every toolchains of given type available in user settings.
     *
     * @param type the type, must not be {@code null}
     * @param context the Maven session, must not be {@code null}
     * @since 3.0 (addition of the <code>MavenSession</code> parameter)
     */

    /**
     * Do not instantiate.
     */
    protected PreparedStatementUtil() {
    }

    /**
     * Executes the query.
     *
     * @param ps
     *            {@link PreparedStatement}. Must not be {@literal null}.
     * @return {@link ResultSet}
     * @throws SQLRuntimeException
     *             If a {@link SQLException} occurs.
     */

     */
    protected AssertionUtil() {
    }

    /**
     * Asserts that the argument is not <code>null</code>.
     *
     * @param argName
     *            The name of the argument that must not be {@code null}.
     * @param argValue
     *            The value of the argument.
     * @throws NullArgumentException
     *             If the argument is <code>null</code>.
     */

    }

    /**
     * Returns whether the class can be assigned from another class.
     *
     * @param toClass
     *            The target class. Must not be {@literal null}.
     * @param fromClass
     *            The source class. Must not be {@literal null}.
     * @return Whether assignment is possible.
     * @see Class#isAssignableFrom(Class)
     */

   *
   * <ul>
   *   <li>Both {@code xStats} and {@code yStats} must have the same {@code count}.
   *   <li>If that {@code count} is 1, {@code sumOfProductsOfDeltas} must be exactly 0.0.
   *   <li>If that {@code count} is more than 1, {@code sumOfProductsOfDeltas} must be finite.
   * </ul>
   */
  PairedStats(Stats xStats, Stats yStats, double sumOfProductsOfDeltas) {

      assertTrue(item + " must not be Object#equals to null", !item.equals(null));
      assertTrue(
          item + " must not be Object#equals to an arbitrary object of another class",
          !item.equals(NotAnInstance.EQUAL_TO_NOTHING));
      assertTrue(item + " must be Object#equals to itself", item.equals(item));
      assertEquals(
          "the Object#hashCode of " + item + " must be consistent",
          item.hashCode(),

     */
    public static void registerDriver(final Class<Driver> driverClass) {
        assertArgumentNotNull("driverClass", driverClass);
        registerDriver(ClassUtil.newInstance(driverClass));
    }

    /**
     * Registers a JDBC driver.
     *
     * @param driver
     *            The JDBC driver to register. Must not be {@literal null}.
     */

     * <code>maven-toolchains-plugin</code> contains the configuration to select the appropriate
     * toolchain and is executed at the beginning of the build.
     *
     * @param type the type, must not be {@code null}
     * @param context the Maven session, must not be {@code null}
     * @return the toolchain selected by <code>maven-toolchains-plugin</code>
     */
    Toolchain getToolchainFromBuildContext(String type, MavenSession context);