/**
     * Returns a new tree starting at this node, filtering the children.
     * Note that this node will not be filtered and only the children
     * and its descendant will be checked.
     *
     * @param filter the filter to apply
     * @return a new filtered graph
     */
    @Nonnull
    Node filter(@Nonnull Predicate<Node> filter);

    /**

import java.io.InvalidObjectException;
import java.io.ObjectInputStream;
import java.io.Serializable;
import java.util.Map.Entry;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * {@code entrySet()} implementation for {@link ImmutableMap}.
 *
 * @author Jesse Wilson
 * @author Kevin Bourrillion
 */
@GwtCompatible(emulated = true)

import com.google.common.collect.testing.features.CollectionSize;
import com.google.common.collect.testing.features.MapFeature;
import java.util.Collection;
import java.util.Map.Entry;
import org.checkerframework.checker.nullness.qual.Nullable;
import org.junit.Ignore;

/**
 * Tester for the {@code size} methods of {@code Multimap} and its views.
 *
 * @author Louis Wasserman
 */
@GwtCompatible

import com.google.common.base.Preconditions;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.nio.ByteBuffer;
import java.nio.charset.Charset;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * An abstract implementation of {@link Hasher}, which only requires subtypes to implement {@link
 * #putByte}. Subtypes may provide more efficient implementations, however.
 *

import static com.google.common.graph.TestUtil.ERROR_ELEMENT_NOT_IN_GRAPH;
import static com.google.common.truth.Truth.assertWithMessage;

import com.google.common.testing.AbstractPackageSanityTests;

/**
 * Covers basic sanity checks for the entire package.
 *
 * @author Kurt Alfred Kluever
 */

public class PackageSanityTests extends AbstractPackageSanityTests {

  private static final AbstractGraphBuilder<?> GRAPH_BUILDER_A =

	// Add more supported headers here.
}

// isDirectiveValid - check if tagging-directive is valid.
func isDirectiveValid(v string) bool {
	// Check if set metadata-directive is valid.
	return isDirectiveCopy(v) || isDirectiveReplace(v)
}

// Check if the directive COPY is requested.
func isDirectiveCopy(value string) bool {
	// By default if directive is not set we

	config.Lock()
	defer config.Unlock()

	// check if tier name is in all caps
	tierName := tier.Name
	if tierName != strings.ToUpper(tierName) {
		return errTierNameNotUppercase
	}

	// check if tier name already in use
	if _, exists := config.isTierNameInUse(tierName); exists {
		return errTierAlreadyExists
	}

	// username in authentication request matches to identities in certificate
	// and that certificate type is correct.
	checker := ssh.CertChecker{}
	checker.IsUserAuthority = func(k ssh.PublicKey) bool {
		return subtle.ConstantTimeCompare(caPublicKey.Marshal(), k.Marshal()) == 1
	}

	_, err = checker.Authenticate(c, clientKey)
	return
}

type sftpLogger struct{}

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import junit.framework.TestCase;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * This abstract base class for testers allows the framework to inject needed information after
 * JUnit constructs the instances.
 *
 * <p>This class is emulated in GWT.
 *

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import junit.framework.TestCase;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * This abstract base class for testers allows the framework to inject needed information after
 * JUnit constructs the instances.
 *
 * <p>This class is emulated in GWT.
 *