absl::Span<AbstractTensorHandle*> grad_inputs) = 0;
  virtual ~GradientFunction() {}
};

// Metadata from the forward operation that is made available to the
// gradient registerer to instantiate a GradientFunction.
struct ForwardOperation {
 public:
  string op_name;
  std::vector<AbstractTensorHandle*> inputs;
  std::vector<AbstractTensorHandle*> outputs;
  std::vector<int64_t> skip_input_indices;

import java.util.Map.Entry;
import org.junit.Ignore;

/**
 * Tests for {@link Multimap#remove(Object, Object)}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")
// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")

 * please see {@link com.google.common.collect.testing.MapTestSuiteBuilder}.
 *
 * @author Chris Povirk
 * @author Kevin Bourrillion
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")
// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")
@NullMarked

import java.util.Map.Entry;
import org.junit.Ignore;

/**
 * Tests for {@link Multimap#remove(Object, Object)}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")
// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")

 * that contain elements.
 *
 * @param <C> the type of the container
 * @param <E> the type of the container's contents
 * @author George van den Driessche
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")
// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")
@NullMarked

import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.w3c.dom.Text;

/**
 * Utility class for DOM operations.
 *
 * @author higa
 */
public abstract class DomUtil {

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

    /**
     * Retrieves the XML content as an {@link InputStream} using the platform's default encoding.
     *
     * @param contents

 * please see {@link com.google.common.collect.testing.MapTestSuiteBuilder}.
 *
 * @author Chris Povirk
 * @author Kevin Bourrillion
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")
// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")

import org.codelibs.core.exception.IORuntimeException;

/**
 * Utility class for handling {@link URL}.
 *
 * @author higa
 */
public abstract class URLUtil {

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

    /** Map for normalizing protocols */
    protected static final Map<String, String> CANONICAL_PROTOCOLS = newHashMap();
    static {

        // Verify that SearchEngineUtil is a utility class with private constructor
        try {
            SearchEngineUtil.class.getDeclaredConstructor().newInstance();
            fail("Should not be able to instantiate utility class");
        } catch (Exception e) {
            // Expected - utility classes should have private constructors

/**
 * Handler for traversing and processing classes.
 *
 * @author koichik
 * @see ClassHandler
 * @see TraversalUtil
 */
public abstract class ClassTraversalUtil {

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

    /** The file extension for class files. */
    protected static final String CLASS_SUFFIX = ".class";

    /** The file extension for WAR files. */