assertEquals("file1.txt", first.getName());

        assertTrue(iterator.hasNext(), "Should have second element");
        SmbResource second = iterator.next();
        assertNotNull(second, "Second element should not be null");
        assertEquals("file2.txt", second.getName());

        assertTrue(iterator.hasNext(), "Should have third element");
        SmbResource third = iterator.next();

    public int compare(@Nullable String first, @Nullable String second) {
      if (first == second) {
        return 0;
      } else if (first == null) {
        return -1;
      } else if (second == null) {
        return 1;
      } else if (first.length() != second.length()) {
        return first.length() - second.length();
      } else {
        return first.compareTo(second);
      }
    }
  }

        Subject first = auth.getSubject();

        // Second call should return cached value (same as first)
        Subject second = auth.getSubject();
        if (first == null && second == null) {
            // Both null - caching is working
            assertNull(second, "Second getSubject should return same result as first (both null)");
        } else if (first != null && second != null) {
            // Both non-null - should be same instance

            assertEquals(second, third.next());
            assertEquals(referralData, second.next());
        }

        @Test
        @DisplayName("Should handle next() correctly")
        void testNext() {
            DfsReferralDataImpl second = new DfsReferralDataImpl();
            referralData.append(second);

            DfsReferralDataImpl next = referralData.next();
            assertSame(second, next);
        }

   * @param second the second array of elements to concatenate
   * @param type the component type of the returned array
   */
  @GwtIncompatible // Array.newInstance(Class, int)
  public static <T extends @Nullable Object> T[] concat(
      T[] first, T[] second, Class<@NonNull T> type) {
    T[] result = newArray(type, first.length + second.length);
    arraycopy(first, 0, result, 0, first.length);

    void testJoinWithStringBuilder() {
        StringBuilder sb1 = new StringBuilder("first");
        StringBuilder sb2 = new StringBuilder("second");
        String result = StringUtil.join(",", sb1, sb2);
        assertEquals("first,second", result);
    }

    @Test
    @DisplayName("Should handle StringBuffer as CharSequence")
    void testJoinWithStringBuffer() {

        assertTrue(r1.getName().endsWith("/"), "Name should end with '/'");

        assertTrue(itr.hasNext(), "Should have second element ready");
        SmbResource r2 = itr.next();
        assertNotNull(r2, "Second adapted resource must not be null");
        assertTrue(r2.getName().endsWith("/"), "Name should end with '/'");

   * @param second the second array of elements to concatenate
   * @param type the component type of the returned array
   */
  @GwtIncompatible // Array.newInstance(Class, int)
  public static <T extends @Nullable Object> T[] concat(
      T[] first, T[] second, Class<@NonNull T> type) {
    T[] result = newArray(type, first.length + second.length);
    arraycopy(first, 0, result, 0, first.length);

      if (first == null) {
        actionWhenFirstParamIsNull.act();
      }
      if (second == null) {
        actionWhenSecondParamIsNull.act();
      }
    }

    /** Two-arg method with no Nullable params. */
    public void normalNormal(String first, Integer second) {
      reactToNullParameters(first, second);
    }

        ChannelInfo second = loadBalancer.selectChannel(mockMessage);

        assertNotNull(first);
        assertNotNull(second);
        // Due to round-robin, should get different channels or same order
        assertTrue(Arrays.asList(channel1, channel2).contains(first));
        assertTrue(Arrays.asList(channel1, channel2).contains(second));
    }

    @Test