* are inherently approximate, routinely affected by periodic clock corrections. Because this class
 * (by default) uses {@link System#nanoTime}, it is unaffected by these changes.
 *
 * <p>Use this class instead of direct calls to {@link System#nanoTime} for two reasons:
 *
 * <ul>
 *   <li>The raw {@code long} values returned by {@code nanoTime} are meaningless and unsafe to use

import com.google.common.annotations.J2ktIncompatible;
import javax.annotation.CheckForNull;

/**
 * Represents a {@linkplain System#getProperties() standard system property}.
 *
 * @author Kurt Alfred Kluever
 * @since 15.0
 */
@J2ktIncompatible
@GwtIncompatible // java.lang.System#getProperty
@ElementTypesAreNonnullByDefault
public enum StandardSystemProperty {

  /** Java Runtime Environment version. */

    // Hack to load AbstractFuture et. al. in a new classloader so that it re-reads the cancellation
    // cause system property.  This allows us to run with both settings of the property in one jvm
    // without resorting to even crazier hacks to reset static final boolean fields.
    System.setProperty("guava.concurrent.generate_cancellation_cause", "true");
    final String concurrentPackage = SettableFuture.class.getPackage().getName();

 *   <li>In at least one case, a use of {@code sun.misc.FpUtils}, the test will not even
 *       <i>compile</i> against Android. Now, this might be an artifact of our build system, one
 *       that we could probably work around. Or we could manually strip the test from open-source
 *       Guava while continuing to run it internally, as we do with many other tests. This would

  }

  @Benchmark
  public int collapseFrom(int reps) {
    int result = 0;
    CharMatcher matcher = this.matcher;
    String teststring = this.teststring;
    for (int i = 0; i < reps; i++) {
      result += System.identityHashCode(matcher.collapseFrom(teststring, ' '));
    }
    return result;
  }

  private static String allMatchingChars(BitSet bitSet) {
    final char[] result = new char[bitSet.cardinality()];

      res +=
          System.identityHashCode(
              hashFunctionEnum
                  .getHashFunction()
                  .hashString(strings[i & SAMPLE_MASK], StandardCharsets.UTF_8));
    }
    return res;
  }

  @Benchmark
  int hashUtf8Hasher(int reps) {
    int res = 0;
    for (int i = 0; i < reps; i++) {
      res +=
          System.identityHashCode(

    out.write(data);
    assertTrue(Arrays.equals(data, source.read()));

    out.close();
  }

  private static boolean isAndroid() {
    return System.getProperty("java.runtime.name", "").contains("Android");
  }

  private static boolean isWindows() {
    return OS_NAME.value().startsWith("Windows");
  }

    long initialSize = cache.size();
    assertTrue(initialSize == 1 || initialSize == 2);

    // wait up to 5s
    byte[] filler = new byte[1024];
    for (int i = 0; i < 500; i++) {
      System.gc();

      CacheTesting.drainReferenceQueues(cache);
      if (cache.size() == 1) {
        break;
      }
      try {
        Thread.sleep(10);
      } catch (InterruptedException e) {

      assertEquals(expected, property.key());
    }
  }

  public void testGetValue() {
    for (StandardSystemProperty property : StandardSystemProperty.values()) {
      assertEquals(System.getProperty(property.key()), property.value());
    }
  }

  public void testToString() {
    for (StandardSystemProperty property : StandardSystemProperty.values()) {

import java.net.URLClassLoader;

// TODO(b/65488446): Make this a public API.
/** Utility method to parse the system class path. */
final class ClassPathUtil {
  private ClassPathUtil() {}

  /**
   * Returns the URLs in the class path specified by the {@code java.class.path} {@linkplain
   * System#getProperty system property}.
   */
  // TODO(b/65488446): Make this a public API.
  static URL[] parseJavaClassPath() {