assertFalse(writer.closed());
    source.copyTo(writer);
    assertFalse(writer.closed());
  }

  public void testClosesOnErrors_copyingToCharSinkThatThrows() {
    for (TestOption option : EnumSet.of(OPEN_THROWS, WRITE_THROWS, CLOSE_THROWS)) {
      TestCharSource okSource = new TestCharSource(STRING);
      assertThrows(IOException.class, () -> okSource.copyTo(new TestCharSink(option)));

    assertFalse(writer.closed());
    source.copyTo(writer);
    assertFalse(writer.closed());
  }

  public void testClosesOnErrors_copyingToCharSinkThatThrows() {
    for (TestOption option : EnumSet.of(OPEN_THROWS, WRITE_THROWS, CLOSE_THROWS)) {
      TestCharSource okSource = new TestCharSource(STRING);
      assertThrows(IOException.class, () -> okSource.copyTo(new TestCharSink(option)));

   *       one with {@link CharSequence#charAt(int)}.
   *   <li>use {@link Appendable#append(CharSequence)} in {@link #copyTo(Appendable)} and {@link
   *       #copyTo(CharSink)}. We know this is correct since strings are immutable and so the length
   *       can't change, and it is faster because many writers and appendables are optimized for

   *       one with {@link CharSequence#charAt(int)}.
   *   <li>use {@link Appendable#append(CharSequence)} in {@link #copyTo(Appendable)} and {@link
   *       #copyTo(CharSink)}. We know this is correct since strings are immutable and so the length
   *       can't change, and it is faster because many writers and appendables are optimized for

    return concat(ImmutableList.copyOf(sources));
  }

  /**
   * Returns a view of the given byte array as a {@link ByteSource}. To view only a specific range
   * in the array, use {@code ByteSource.wrap(b).slice(offset, length)}.
   *
   * <p>Note that the given byte array may be passed directly to methods on, for example, {@code
   * OutputStream} (when {@code copyTo(OutputStream)} is called on the resulting {@code

     *
     * In this case the current thread is assigned as the upstream reader. We read bytes from
     * upstream and copy them to both the file and to the buffer. Finally we release the upstream
     * reader lock and return the new bytes.
     *
     * ## The file
     *
     * In this case we copy bytes from the file to the [sink].
     *
     * ## The buffer
     *

   * @deprecated Prefer {@code asCharSource(from, charset).copyTo(to)}.
   */
  @Deprecated
  @InlineMe(
      replacement = "Files.asCharSource(from, charset).copyTo(to)",
      imports = "com.google.common.io.Files")
  public
  static void copy(File from, Charset charset, Appendable to) throws IOException {
    asCharSource(from, charset).copyTo(to);
  }

  /**

   * @deprecated Prefer {@code asCharSource(from, charset).copyTo(to)}.
   */
  @Deprecated
  @InlineMe(
      replacement = "Files.asCharSource(from, charset).copyTo(to)",
      imports = "com.google.common.io.Files")
  public
  static void copy(File from, Charset charset, Appendable to) throws IOException {
    asCharSource(from, charset).copyTo(to);
  }

  /**

        @Test
        @DisplayName("copy operation should work correctly")
        void testCopyTo() throws CIFSException {
            // Given
            SmbResource destination = mock(SmbResource.class);

            // When/Then
            assertDoesNotThrow(() -> mockResource.copyTo(destination), "Copy operation should not throw exception");
            verify(mockResource).copyTo(destination);
        }

        @Test

            if (!cacheRequestClosed) {
              cacheRequestClosed = true
              cacheBody.close() // The cache response is complete!
            }
            return -1
          }

          sink.copyTo(cacheBody.buffer, sink.size - bytesRead, bytesRead)
          cacheBody.emitCompleteSegments()
          return bytesRead
        }

        override fun timeout(): Timeout = source.timeout()