* necessary.
   *
   * <p>The returned iterator supports {@code remove()} when the corresponding input iterator
   * supports it.
   *
   * @throws NullPointerException if any of the provided iterators is null
   */
  @SafeVarargs
  public static <T extends @Nullable Object> Iterator<T> concat(Iterator<? extends T>... inputs) {

 *  Fix: Don't close a `Deflater` while we're still using it to compress a web socket message. We
    had a severe bug where web sockets were closed on the wrong thread, which caused
    `NullPointerException` crashes in `Deflater`.

 *  Fix: Don't crash after a web socket fails its connection upgrade. We incorrectly released
    the web socket's connections back to the pool before their resources were cleaned up.

        }
      }
    }
  }

  public void testToArray_withNull() {
    List<@Nullable Character> list = Arrays.asList((char) 0, (char) 1, null);
    assertThrows(NullPointerException.class, () -> Chars.toArray(list));
  }

  @J2ktIncompatible // b/285319375
  public void testAsList_isAView() {
    char[] array = {(char) 0, (char) 1};
    List<Character> list = Chars.asList(array);

        // Register should fail with null container
        try {
            ruleWithoutContainer.register(0);
            fail("Should throw exception with null container");
        } catch (NullPointerException e) {
            // Expected
        }
    }

    /**
     * Test concurrent property access
     */
    public void test_concurrentPropertyAccess() throws Exception {

   * We don't permit nulls, but we wrap every comparator with nullsFirst().
   * Why? We want for queries like containsKey(null) to return false, but the
   * GWT SortedMap implementation that we delegate to throws
   * NullPointerException if the comparator does. Since our construction
   * methods ensure that null is never present in the map, it's OK for the
   * comparator to look for it wherever it wants.
   *

            request.setData(null, 0, 100);

            byte[] buffer = new byte[256];

            // Should handle gracefully or throw appropriate exception
            assertThrows(NullPointerException.class, () -> request.writeBytesWireFormat(buffer, 0));
        }

        @Test
        @DisplayName("Should handle data offset beyond array bounds")
        void testDataOffsetBeyondBounds() {

      List<E> extremeValues = new ArrayList<>();

      // nulls are usually out of bounds for a subset, so ban them altogether
      for (Object o : elements) {
        if (o == null) {
          throw new NullPointerException();
        }
      }

      // prepare extreme values to be filtered out of view
      E firstExclusive = delegate.belowSamplesGreater();
      E lastExclusive = delegate.aboveSamplesLesser();

  /**
   * A function equivalent to the method reference {@code Object::toString}. The function simply
   * invokes {@code toString} on its argument and returns the result. It throws a {@link
   * NullPointerException} on null input.
   *
   * <p><b>Warning:</b> The returned function may not be <i>consistent with equals</i> (as
   * documented at {@link Function#apply}). For example, this function yields different results for

          @Override
          public String toString() {
            throw new NullPointerException();
          }
        });
    assertThat(orig.toString())
        .contains(
            "[status=PENDING, setFuture=[Exception thrown from implementation: class"
                + " java.lang.NullPointerException]]");
  }

  @AndroidIncompatible // b/391667564: crashes from stack overflows

 * converted to strings using {@link Object#toString()} before being appended.
 *
 * <p>If neither {@link #skipNulls()} nor {@link #useForNull(String)} is specified, the joining
 * methods will throw {@link NullPointerException} if any given element is null.
 *
 * <p><b>Warning: joiner instances are always immutable</b>; a configuration method such as {@code