}

    // Demonstrates observed equals() asymmetry when this is shorter than argument
    @Test
    @DisplayName("equals: this shorter but same prefix -> true (observed behavior)")
    void equals_thisShorterSamePrefix_true_dueToImplementation() {
        // Arrange: left shorter than right but with identical prefix

   * A word about using {@link Equivalence}, which automatically checks for {@code null} and
   * identical inputs: This sounds like it ought to be a problem here, since the goals of this class
   * include testing that {@code equals()} is reflexive and is tolerant of {@code null}. However,
   * there's no problem. The reason: {@link EqualsTester} tests {@code null} and identical inputs
   * directly against {@code equals()} rather than through the {@code Equivalence}.

    }

    /**
     * Finish building an instance which also maps {@code x = x2} to {@code y = y2}. These values
     * must not both be identical to the values given in the first mapping. If only the {@code x}
     * values are identical, the transformation is vertical. If only the {@code y} values are
     * identical, the transformation is horizontal (i.e. the slope is zero).
     */
    public LinearTransformation and(double x2, double y2) {

    assertEquals("a", Strings.commonPrefix("abc", "aaaaa"));
    assertEquals("aa", Strings.commonPrefix("aa", "aaaaa"));
    assertEquals("abc", Strings.commonPrefix(new StringBuilder("abcdef"), "abcxyz"));

    // Identical valid surrogate pairs.
    assertEquals(
        "abc\uD8AB\uDCAB", Strings.commonPrefix("abc\uD8AB\uDCABdef", "abc\uD8AB\uDCABxyz"));
    // Differing valid surrogate pairs.

   * A word about using {@link Equivalence}, which automatically checks for {@code null} and
   * identical inputs: This sounds like it ought to be a problem here, since the goals of this class
   * include testing that {@code equals()} is reflexive and is tolerant of {@code null}. However,
   * there's no problem. The reason: {@link EqualsTester} tests {@code null} and identical inputs
   * directly against {@code equals()} rather than through the {@code Equivalence}.

            assertArrayEquals(firstEncoding, secondEncoding, "First and second encoding should be identical");
            assertArrayEquals(secondEncoding, thirdEncoding, "Second and third encoding should be identical");

            // Verify content preservation
            assertArrayEquals(mechs, parsed2.getMechanisms());
            assertEquals(flags, parsed2.getContextFlags());

import java.util.Collection;
import java.util.Set;
import org.jspecify.annotations.NullUnmarked;

/**
 * Variant of {@link SerializableTester} that does not require the reserialized object's class to be
 * identical to the original.
 *
 * @author Chris Povirk
 */
/*
 * The whole thing is really @GwtIncompatible, but GwtJUnitConvertedTestModule doesn't have a

  // defaults

  /**
   * Copies all characters between the {@link Reader} and {@link StringBuilder} objects. Does not
   * close or flush the reader.
   *
   * <p>This is identical to {@link #copy(Readable, Appendable)} but optimized for these specific
   * types. CharBuffer has poor performance when being written into or read out of so round tripping

/// tip

   */
  public static <N> Graph<N> transpose(Graph<N> graph) {
    if (!graph.isDirected()) {
      return graph; // the transpose of an undirected graph is an identical graph
    }

    if (graph instanceof TransposedGraph) {
      return ((TransposedGraph<N>) graph).graph;
    }

    return new TransposedGraph<>(graph);
  }

  /**