}

  @GwtIncompatible // java.util.regex.Pattern
  public void testPatternSplitWordBoundary_singleCharInput() {
    String string = "f";
    Iterable<String> words = Splitter.on(Pattern.compile("\\b")).split(string);
    assertThat(words).containsExactly("f").inOrder();
  }

  @AndroidIncompatible // Apparently Gingerbread's regex API is buggy.
  @J2ktIncompatible // Kotlin Native's regex is based on Apache Harmony, like old Android

import com.google.common.testing.NullPointerTester;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.io.InputStream;
import java.nio.charset.Charset;
import java.util.concurrent.TimeUnit;
import java.util.regex.Pattern;
import junit.framework.AssertionFailedError;
import junit.framework.TestCase;
import org.checkerframework.checker.nullness.qual.Nullable;

/**

package com.google.common.base;

import com.google.common.annotations.GwtIncompatible;
import com.google.errorprone.annotations.RestrictedApi;

/**
 * Pluggable interface for compiling a regex pattern. By default this package uses the {@code
 * java.util.regex} library, but an alternate implementation can be supplied using the {@link
 * java.util.ServiceLoader} mechanism.
 */
@GwtIncompatible
@ElementTypesAreNonnullByDefault

  }

  /**
   * This is adapted from the regex suggested by {@link Double#valueOf(String)} for prevalidating
   * inputs. All valid inputs must pass this regex, but it's semantically fine if not all inputs
   * that pass this regex are valid -- only a performance hit is incurred, not a semantics bug.
   */
  @GwtIncompatible // regular expressions
  static final
  java.util.regex.Pattern
      FLOATING_POINT_PATTERN = fpPattern();

import com.google.common.annotations.J2ktIncompatible;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.List;
import java.util.regex.Pattern;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Static utility methods pertaining to {@code Predicate} instances.
 *

import java.util.SortedMap;
import java.util.SortedSet;
import java.util.TreeMap;
import java.util.TreeSet;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.regex.Pattern;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Generates fresh instances of types that are different from each other (if possible).
 *

import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.util.regex.MatchResult;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.stream.Stream;
import org.checkerframework.checker.nullness.qual.Nullable;

/**

import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.util.regex.MatchResult;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Supplies an arbitrary "default" instance for a wide range of types, often useful in testing
 * utilities.

import com.google.common.testing.NullPointerTester;
import com.google.common.testing.NullPointerTester.Visibility;
import java.io.File;
import java.io.FilenameFilter;
import java.util.regex.PatternSyntaxException;
import junit.framework.TestCase;

/**
 * Unit test for {@link PatternFilenameFilter}.
 *
 * @author Chris Nokleberg
 */
public class PatternFilenameFilterTest extends TestCase {

import java.util.Collections;
import java.util.EnumMap;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.stream.Collector;
import java.util.stream.Stream;
import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;