## Conflict Resolution

   * is unnecessary; for example, {@code copyOf(copyOf(anArrayList))} will copy the data only once.
   * This reduces the expense of habitually making defensive copies at API boundaries. However, the
   * precise conditions for skipping the copy operation are undefined.
   *
   * @throws NullPointerException if any of {@code elements} is null

          Function<? super T, ? extends K> keyFunction,
          Function<? super T, ? extends V> valueFunction) {
    return CollectCollectors.toImmutableBiMap(keyFunction, valueFunction);
  }

  // Casting to any type is safe because the set will never hold any elements.
  @SuppressWarnings("unchecked")
  public static <K, V> ImmutableBiMap<K, V> of() {
    return (ImmutableBiMap<K, V>) RegularImmutableBiMap.EMPTY;
  }

      "You" (or "Your") shall mean an individual or Legal Entity
      exercising permissions granted by this License.

      "Source" form shall mean the preferred form for making modifications,
      including but not limited to software source code, documentation
      source, and configuration files.

      "Object" form shall mean any form resulting from mechanical

      "You" (or "Your") shall mean an individual or Legal Entity
      exercising permissions granted by this License.

      "Source" form shall mean the preferred form for making modifications,
      including but not limited to software source code, documentation
      source, and configuration files.

      "Object" form shall mean any form resulting from mechanical

	//
	// Some newer formats add their own extensions to PAX by defining their
	// own keys and assigning certain semantic meaning to the associated values.
	// For example, sparse file support in PAX is implemented using keys
	// defined by the GNU manual (e.g., "GNU.sparse.map").
	//
	// Reference:
	//	http://pubs.opengroup.org/onlinepubs/009695399/utilities/pax.html
	FormatPAX

  fi

  if [[ -s $BATS_TEST_TMPDIR/actual_missing_licenses ]]; then
    echo "Please include the missing licenses for the following packages in $LICENSES_TARGET:"
    cat $BATS_TEST_TMPDIR/actual_missing_licenses
  fi

  # Fail if either of the two "extras" or "missing" lists are present. If so,
  # then the user will see the above error messages.

It also re-declares `id: int`. By doing this, we are making a **contract** with the API clients, so that they can always expect the `id` to be there and to be an `int` (it will never be `None`).

/// tip

Having the return model ensure that a value is always available and always `int` (not `None`) is very useful for the API clients, they can write much simpler code having this certainty.

application-layer can also do blocking reads. If the application asks to read and there's nothing available, we need to hold that thread until either the bytes arrive, the stream is closed, or a timeout elapses. If we get bytes but there's nobody asking for them, we buffer them. We don't consider bytes as delivered for flow control until they're consumed by the application.

Consider an application streaming a video over http/2. Perhaps the user pauses the video and the application stops...

    @GwtIncompatible @J2ktIncompatible private static final long serialVersionUID = 0;
  }

  /**
   * Returns a supplier whose {@code get()} method synchronizes on {@code delegate} before calling
   * it, making it thread-safe.
   */
  @J2ktIncompatible
  public static <T extends @Nullable Object> Supplier<T> synchronizedSupplier(
      Supplier<T> delegate) {
    return new ThreadSafeSupplier<>(delegate);
  }