*       implementation will effectively put the whole file in memory. On many systems with paging
   *       and virtual memory, this is not a problem - because it is mapped read-only, the kernel
   *       can always page it to disk "for free". However, on systems where killing processes
   *       happens all the time in normal conditions (i.e., android) the OS must make a tradeoff

  static final boolean GENERATE_CANCELLATION_CAUSES;

  static {
    // System.getProperty may throw if the security policy does not permit access.
    boolean generateCancellationCauses;
    try {
      generateCancellationCauses =
          Boolean.parseBoolean(
              System.getProperty("guava.concurrent.generate_cancellation_cause", "false"));
    } catch (SecurityException e) {

    checkNotNull(file1);
    checkNotNull(file2);
    if (file1 == file2 || file1.equals(file2)) {
      return true;
    }

    /*
     * Some operating systems may return zero as the length for files denoting system-dependent
     * entities such as devices or pipes, in which case we must fall back on comparing the bytes
     * directly.
     */
    long len1 = file1.length();

     * than relying on the one from the system property.
     *
     * - Under Java 8, createTempDir() fails because it falls back to the bogus username from the
     * system property.
     */

    String save = System.getProperty("user.name");
    System.setProperty("user.name", "-this-is-definitely-not-the-username-we-are-running-as//?");
    try {

    else super.runTest();
  }

  protected void runTestProfiled() throws Throwable {
    long t0 = System.nanoTime();
    try {
      super.runTest();
    } finally {
      long elapsedMillis = (System.nanoTime() - t0) / (1000L * 1000L);
      if (elapsedMillis >= profileThreshold)
        System.out.printf("%n%s: %d%n", toString(), elapsedMillis);
    }
  }

  //     /**

    // 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();

  }

  /**
   * Returns System.nanoTime() unless the timeout has already elapsed. Returns 0L if and only if the
   * timeout has already elapsed.
   */
  private static long initNanoTime(long timeoutNanos) {
    if (timeoutNanos <= 0L) {
      return 0L;
    } else {
      long startTime = System.nanoTime();
      return (startTime == 0L) ? 1L : startTime;
    }
  }

    }
    assertEquals(oldName, Thread.currentThread().getName());
  }

  @J2ktIncompatible
  @GwtIncompatible // threads

  public void testRenaming_noPermissions() throws Exception {
    System.setSecurityManager(
        new SecurityManager() {
          @Override
          public void checkAccess(Thread t) {
            throw new SecurityException();
          }

          @Override

    }
  }

  private static Long[] concat(Long[] left, Long[] right) {
    Long[] result = new Long[left.length + right.length];
    System.arraycopy(left, 0, result, 0, left.length);
    System.arraycopy(right, 0, result, left.length, right.length);
    return result;
  }

  public abstract static class TestLongListGenerator implements TestListGenerator<Long> {
    @Override

        : parseJavaClassPath().toArray(new URL[0]);
  }

  /**
   * 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.
  @J2ktIncompatible
  @GwtIncompatible
  private static ImmutableList<URL> parseJavaClassPath() {