public String getMethod() {
            return null;
        }

        @Override
        public Long getLastModified() {
            return null;
        }

        @Override
        public String getSessionId() {
            return null;
        }

        @Override
        public Long getCreateTime() {
            return null;
        }

        @Override

      return this;
    }

    @Override
    public Writer append(@Nullable CharSequence csq, int start, int end) {
      checkPositionIndexes(start, end, csq == null ? "null".length() : csq.length());
      return this;
    }

    @Override
    public Writer append(char c) {
      return this;
    }

    @Override
    public void flush() {}

    }

    public void test_constructor_withNullUsername() {
        // Test with null username
        String username = null;
        FessUserNotFoundException exception = new FessUserNotFoundException(username);

        assertNotNull(exception);
        assertEquals("User is not found: null", exception.getMessage());
        assertNull(exception.getCause());
    }

    List<V> values = asList(v0(), null, v3());
    multimap().replaceValues(k0(), values);
    assertGet(k0(), values);
  }

  @MapFeature.Require({SUPPORTS_PUT, SUPPORTS_REMOVE, ALLOWS_NULL_KEYS})
  public void testReplaceValuesWithNullKey() {
    List<V> values = asList(v0(), v2(), v3());
    multimap().replaceValues(null, values);
    assertGet(null, values);
  }

  ImmutableCollection() {}

  @Override
  public abstract UnmodifiableIterator<E> iterator();

  @Override
  public boolean contains(@Nullable Object object) {
    return object != null && super.contains(object);
  }

  @Override
  public final boolean add(E e) {
    throw new UnsupportedOperationException();
  }

  @Override
  public final boolean remove(@Nullable Object object) {

    /**
     * GETs the source URI content as byte array. The source MUST BE relative from the {@link RemoteRepository#getUrl()}
     * root.
     *
     * @return the byte array if operation succeeded, {@code null} if source does not exist.
     * @throws RuntimeException If failed (and not due source not exists).
     */
    @Nonnull
    Optional<byte[]> getBytes(@Nonnull URI relativeSource);

    /**

            assertEquals(expiration, response.getExpiration());
        }

        @Test
        @DisplayName("Should handle null expiration")
        void testNullExpiration() {
            response.setExpiration(null);

            assertNull(response.getExpiration());
        }
    }

    @Nested
    @DisplayName("Async Handling Tests")
    class AsyncHandlingTests {

    public boolean chain(final ServerMessageBlock2 n) {
        if (this.next != null) {
            return this.next.chain(n);
        }

        n.addFlags(SMB2_FLAGS_RELATED_OPERATIONS);
        this.next = n;
        return true;
    }

    /**
     * Gets the next message in the compound chain.
     *
     * @return the next message or null if this is the last message
     */

  public T or(Supplier<? extends T> supplier) {
    return checkNotNull(
        supplier.get(), "use Optional.orNull() instead of a Supplier that returns null");
  }

  @Override
  public @Nullable T orNull() {
    return null;
  }

  @Override
  public Set<T> asSet() {
    return Collections.emptySet();
  }

  @Override
  public <V> Optional<V> transform(Function<? super T, V> function) {
    checkNotNull(function);

    this.ordering = ordering;
  }

  @Override
  public int compare(@Nullable T left, @Nullable T right) {
    if (left == right) {
      return 0;
    }
    if (left == null) {
      return RIGHT_IS_GREATER;
    }
    if (right == null) {
      return LEFT_IS_GREATER;
    }
    return ordering.compare(left, right);
  }

  @Override