assertSame(s1, s2);

    Long n1 = 42L;
    Long n2 = MoreObjects.firstNonNull(null, n1);
    assertSame(n1, n2);

    Boolean b1 = true;
    Boolean b2 = MoreObjects.firstNonNull(b1, null);
    assertSame(b1, b2);
  }

  public void testFirstNonNull_throwsNullPointerException() {
    assertThrows(NullPointerException.class, () -> MoreObjects.firstNonNull(null, null));
  }

    assertSame(s1, s2);

    Long n1 = 42L;
    Long n2 = MoreObjects.firstNonNull(null, n1);
    assertSame(n1, n2);

    Boolean b1 = true;
    Boolean b2 = MoreObjects.firstNonNull(b1, null);
    assertSame(b1, b2);
  }

  public void testFirstNonNull_throwsNullPointerException() {
    assertThrows(NullPointerException.class, () -> MoreObjects.firstNonNull(null, null));
  }

import javax.inject.Named;
import javax.inject.Singleton;

/**
 * Wagon for testing, for protocols <code>b1</code> and <code>b2</code>
 *
 */
@Named("b")
@Singleton
public class WagonB extends WagonMock {
    public String[] getSupportedProtocols() {
        return new String[] {"b1", "b2"};
    }

    ByteSource b1 = ByteSource.wrap(new byte[] {0, 1, 2, 3});
    ByteSource b2 = ByteSource.wrap(new byte[0]);
    ByteSource b3 = ByteSource.wrap(new byte[] {4, 5});

    byte[] expected = {0, 1, 2, 3, 4, 5};

    assertArrayEquals(expected, ByteSource.concat(ImmutableList.of(b1, b2, b3)).read());
    assertArrayEquals(expected, ByteSource.concat(b1, b2, b3).read());

    ByteSource b1 = ByteSource.wrap(new byte[] {0, 1, 2, 3});
    ByteSource b2 = ByteSource.wrap(new byte[0]);
    ByteSource b3 = ByteSource.wrap(new byte[] {4, 5});

    byte[] expected = {0, 1, 2, 3, 4, 5};

    assertArrayEquals(expected, ByteSource.concat(ImmutableList.of(b1, b2, b3)).read());
    assertArrayEquals(expected, ByteSource.concat(b1, b2, b3).read());

     * <pre>
     * a:1.0
     * b:1.0 -&gt; a:2.0
     * </pre>
     */
    @Test
    void testDepth() {
        ResolutionNode a1n = createResolutionNode(a1);
        ResolutionNode b1n = createResolutionNode(b1);
        ResolutionNode a2n = createResolutionNode(a2, b1n);

        assertResolveConflict(a2n, a1n, a2n);
    }

    /**
     * Tests that <code>a:2.0</code> wins in the scenario:
     * <pre>

     * <pre>
     * a:1.0
     * b:1.0 -&gt; a:2.0
     * </pre>
     */
    @Test
    void testDepth() {
        ResolutionNode a1n = createResolutionNode(a1);
        ResolutionNode b1n = createResolutionNode(b1);
        ResolutionNode a2n = createResolutionNode(a2, b1n);

        assertResolveConflict(a1n, a1n, a2n);
    }

    /**
     * Tests that <code>a:1.0</code> wins in the scenario:
     * <pre>

     * <pre>
     * a:1.0
     * b:1.0 -&gt; a:2.0
     * </pre>
     */
    @Test
    void testDepth() {
        ResolutionNode a1n = createResolutionNode(a1);
        ResolutionNode b1n = createResolutionNode(b1);
        ResolutionNode a2n = createResolutionNode(a2, b1n);

        assertResolveConflict(a1n, a1n, a2n);
    }

    /**
     * Tests that <code>a:1.0</code> wins in the scenario:
     * <pre>

     * <pre>
     * a:1.0
     * b:1.0 -&gt; a:2.0
     * </pre>
     */
    @Test
    void testDepth() {
        ResolutionNode a1n = createResolutionNode(a1);
        ResolutionNode b1n = createResolutionNode(b1);
        ResolutionNode a2n = createResolutionNode(a2, b1n);

        assertResolveConflict(a2n, a1n, a2n);
    }

    /**
     * Tests that <code>a:2.0</code> wins in the scenario:
     * <pre>

    private static final String GROUP_ID = "test";

    // fields -----------------------------------------------------------------

    protected Artifact a1;

    protected Artifact a2;

    protected Artifact b1;

    private final String roleHint;

    @Inject
    private ArtifactFactory artifactFactory;

    private ConflictResolver conflictResolver;

    @Inject
    protected PlexusContainer container;