001    package org.junit.runners;
002    
003    import org.junit.runners.model.InitializationError;
004    
005    /**
006     * Aliases the current default JUnit 4 class runner, for future-proofing. If
007     * future versions of JUnit change the default Runner class, they will also
008     * change the definition of this class. Developers wanting to explicitly tag a
009     * class as a JUnit 4 class should use {@code @RunWith(JUnit4.class)}, not,
010     * for example in JUnit 4.5, {@code @RunWith(BlockJUnit4ClassRunner.class)}.
011     * This is the only way this class should be used--any extension that
012     * depends on the implementation details of this class is likely to break
013     * in future versions.
014     *
015     * @since 4.5
016     */
017    public final class JUnit4 extends BlockJUnit4ClassRunner {
018        /**
019         * Constructs a new instance of the default runner
020         */
021        public JUnit4(Class<?> klass) throws InitializationError {
022            super(klass);
023        }
024    }