import com.google.common.base.Preconditions;
import java.io.DataOutput;
import java.io.DataOutputStream;
import java.io.FilterOutputStream;
import java.io.IOException;
import java.io.OutputStream;

/**
 * An implementation of {@link DataOutput} that uses little-endian byte ordering for writing {@code
 * char}, {@code short}, {@code int}, {@code float}, {@code double}, and {@code long} values.
 *

import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.ArrayList;
import java.util.List;
import junit.framework.AssertionFailedError;
import org.jspecify.annotations.NullMarked;

/**
 * Implementation helper for {@link EqualsTester} and {@link EquivalenceTester} that tests for
 * equivalence classes.
 *
 * @author Gregory Kick
 */
@GwtCompatible
@NullMarked
final class RelationshipTester<T> {

          @Override
          protected char @Nullable [] escape(int cp) {
            return ('a' <= cp && cp <= 'z') ? new char[] {Character.toUpperCase((char) cp)} : null;
          }

          // Inefficient implementation that defines all letters as escapable.
          @Override
          protected int nextEscapeIndex(CharSequence csq, int index, int end) {
            while (index < end && !Character.isLetter(csq.charAt(index))) {

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.Arrays;
import org.jspecify.annotations.Nullable;

/**
 * Abstract implementation of {@link InvocationHandler} that handles {@link Object#equals}, {@link
 * Object#hashCode} and {@link Object#toString}. For example:
 *
 * <pre>
 * class Unsupported extends AbstractInvocationHandler {

import java.util.SortedSet;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * Class that contains nested abstract tests for filtered collection views, along with their
 * implementation helpers.
 *
 * @author Louis Wasserman
 */
/*
 * TODO(cpovirk): Should all the tests for filtered collections run under GWT, too? Currently, they
 * don't.
 */
@NullUnmarked

    void testToHexStringByteArray() {
        // Note: The implementation has a bug - it ignores the srcIndex parameter!
        // The third parameter is the size of the output string in characters
        // size = number of hex characters to output
        // Each byte produces 2 hex characters

        // Test basic conversion (srcIndex is ignored in the implementation)
        byte[] data1 = { 0x00, 0x01, 0x02, 0x03 };

### [Fast Fallback](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-ok-http-client/-builder/fast-fallback/)

Since version 5.0, `OkHttpClient` supports fast fallback, which is our implementation of Happy Eyeballs [RFC 6555](https://datatracker.ietf.org/doc/html/rfc6555).

    checkPositionIndex(index, size());
    if (isEmpty()) {
      return (UnmodifiableListIterator<E>) EMPTY_ITR;
    } else {
      return new Itr<E>(this, index);
    }
  }

  /** A singleton implementation of iterator() for the empty ImmutableList. */
  // TODO(b/345814817): Move this to RegularImmutableList?
  @SuppressWarnings("ClassInitializationDeadlock")
  private static final UnmodifiableListIterator<Object> EMPTY_ITR =

            // Get value again - in real FessConfigImpl it would be cached,
            // but our test implementation always checks system properties
            String value2 = fessConfig.get(testKey);
            // In our test implementation, it will pick up the new value
            assertEquals(newValue, value2);
        } finally {
            // Clean up system property

    }

    /**
     * Test call() method as Callable in executor service
     */
    @Test
    void testCallAsCallable() throws Exception {
        // Create a real implementation for testing Callable behavior
        SmbWatchHandle realHandle = new SmbWatchHandle() {
            private int callCount = 0;

            @Override