if (delegate instanceof UnmodifiableMultimap || delegate instanceof ImmutableMultimap) {
      return delegate;
    }
    return new UnmodifiableMultimap<>(delegate);
  }

  /**
   * Simply returns its argument.
   *
   * @deprecated no need to use this
   * @since 10.0
   */
  @InlineMe(
      replacement = "checkNotNull(delegate)",

    if (delegate instanceof UnmodifiableMultimap || delegate instanceof ImmutableMultimap) {
      return delegate;
    }
    return new UnmodifiableMultimap<>(delegate);
  }

  /**
   * Simply returns its argument.
   *
   * @deprecated no need to use this
   * @since 10.0
   */
  @InlineMe(
      replacement = "checkNotNull(delegate)",

 * number of occurrences of {@code "%s"} in the format string, {@code Preconditions} will still
 * behave as expected, and will still include all argument values in the error message; the message
 * will simply not be formatted exactly as intended.
 *
 * <h3>More information</h3>
 *
 * <p>See the Guava User Guide on <a
 * href="https://github.com/google/guava/wiki/PreconditionsExplained">using {@code
 * Preconditions}</a>.

	}
	existingRoot.merge(*otherRoot)
	eHash := d.rootHash()
	for key := range otherRoot.Children {
		entry := other.Cache[key]
		flat := other.flatten(entry)
		existing := d.Cache[key]
		// If not found, merging simply adds.
		existing.merge(flat)
		d.replaceHashed(dataUsageHash(key), &eHash, existing)
	}
}

type objectIO interface {

    assertEquals(1, matcher.countIn(s));
  }

  /**
   * Checks that expected is equals to out, and further, if in is equals to expected, then out is
   * successfully optimized to be identical to in, i.e. that "in" is simply returned.
   */
  private void assertEqualsSame(String expected, String in, String out) {
    if (expected.equals(in)) {
      assertSame(in, out);
    } else {
      assertEquals(expected, out);
    }
  }

   *
   * @return an empty collection of values
   */
  abstract Collection<V> createCollection();

  /**
   * Creates the collection of values for an explicitly provided key. By default, it simply calls
   * {@link #createCollection()}, which is the correct behavior for most implementations. The {@link
   * LinkedHashMultimap} class overrides it.
   *
   * @param key key to associate with values in the collection

  /**
   * Opens a new buffered {@link InputStream} for reading from this source. The returned stream is
   * not required to be a {@link BufferedInputStream} in order to allow implementations to simply
   * delegate to {@link #openStream()} when the stream returned by that method does not benefit from
   * additional buffering (for example, a {@code ByteArrayInputStream}). This method returns a new,

   * may prefer to invoke that method directly; this method exists only for consistency with the
   * other utilities in this package.
   *
   * <p><b>Note:</b> this method simply delegates to the JDK method {@link Float#compare}. It is
   * provided for consistency with the other primitive types, whose compare methods were not added
   * to the JDK until JDK 7.
   *

    assertEquals(1, matcher.countIn(s));
  }

  /**
   * Checks that expected is equals to out, and further, if in is equals to expected, then out is
   * successfully optimized to be identical to in, i.e. that "in" is simply returned.
   */
  private void assertEqualsSame(String expected, String in, String out) {
    if (expected.equals(in)) {
      assertSame(in, out);
    } else {
      assertEquals(expected, out);
    }
  }

   * that of <code>((Double) a).{@linkplain Double#compareTo compareTo}(b)</code>. As with that
   * method, {@code NaN} is treated as greater than all other values, and {@code 0.0 > -0.0}.
   *
   * <p><b>Note:</b> this method simply delegates to the JDK method {@link Double#compare}. It is
   * provided for consistency with the other primitive types, whose compare methods were not added
   * to the JDK until JDK 7.
   *