}

  /**
   * Reads all bytes from a URL into a byte array.
   *
   * @param url the URL to read from
   * @return a byte array containing all the bytes from the URL
   * @throws IOException if an I/O error occurs
   */
  public static byte[] toByteArray(URL url) throws IOException {
    return asByteSource(url).read();
  }

  /**
   * Reads all characters from a URL into a {@link String}, using the given character set.

    assertEquals(-1, reader.read());
    assertEquals(-1, reader.read(new char[10], 0, 10));
    assertEquals(-1, reader.read(CharBuffer.allocate(10)));
    assertEquals(0, reader.skip(10));
  }

  private static String readFully(CharSequenceReader reader) throws IOException {
    StringBuilder builder = new StringBuilder();
    int read;
    while ((read = reader.read()) != -1) {
      builder.append((char) read);

    ByteSource source = out.asByteSource();

    out.write(data);
    assertTrue(Arrays.equals(data, source.read()));

    out.reset();
    assertTrue(Arrays.equals(new byte[0], source.read()));

    out.write(data);
    assertTrue(Arrays.equals(data, source.read()));

    out.close();
  }

  private static boolean isAndroid() {

    }

    @Test
    @DisplayName("readn should handle multiple read calls")
    void testReadnMultipleCalls() throws IOException {
        when(mockInputStream.read(any(byte[].class), anyInt(), anyInt())).thenReturn(2) // First read returns 2 bytes
                .thenReturn(2) // Second read returns 2 bytes
                .thenReturn(1); // Third read returns 1 byte

        byte[] buffer = new byte[10];

        // Read first message
        assertEquals(1, sis.read());
        assertEquals(2, sis.read());

        // Read second message
        assertEquals(3, sis.read());
        assertEquals(4, sis.read());
        assertEquals(5, sis.read());

        // After all data is consumed, next read throws IOException
        assertThrows(IOException.class, () -> sis.read());
    }

    @Test

  - [Urgent Upgrade Notes](#urgent-upgrade-notes)
    - [(No, really, you MUST read this before you upgrade)](#no-really-you-must-read-this-before-you-upgrade)
  - [Changes by Kind](#changes-by-kind-16)
    - [Deprecation](#deprecation)
    - [API Change](#api-change-5)
    - [Feature](#feature-14)

* `write(data)`: Writes `data` (`str` or `bytes`) to the file.
* `read(size)`: Reads `size` (`int`) bytes/characters of the file.
* `seek(offset)`: Goes to the byte position `offset` (`int`) in the file.
    * E.g., `await myfile.seek(0)` would go to the start of the file.
    * This is especially useful if you run `await myfile.read()` once and then need to read the contents again.
* `close()`: Closes the file.

    val source = relay.newSource()
    val sourceBuffer = Buffer()
    assertThat(source!!.read(sourceBuffer, 5)).isEqualTo(5)
    assertThat(sourceBuffer.readUtf8()).isEqualTo("abcde")
    assertThat(source.read(sourceBuffer, 1024)).isEqualTo(8)
    assertThat(sourceBuffer.readUtf8()).isEqualTo("fghijklm")
    assertThat(source.read(sourceBuffer, 1024)).isEqualTo(-1)
    assertThat(sourceBuffer.size).isEqualTo(0)
    source.close()

            SMBUtil.writeInt2(17, buffer, 0); // Structure size
            SMBUtil.writeInt2(0, buffer, 2); // Reserved
            SMBUtil.writeInt4(-1, buffer, 4); // Count (will be read as unsigned)
            SMBUtil.writeInt4(-2, buffer, 8); // Remaining (will be read as unsigned)
            SMBUtil.writeInt4(0, buffer, 12); // WriteChannelInfoOffset/Length

            int bytesRead = response.readBytesWireFormat(buffer, 0);

    val buffer = Buffer()
    operator.read(6, buffer, 21)
    operator.read(36, buffer, 1)
    operator.read(5, buffer, 5)
    operator.read(28, buffer, 8)
    operator.read(17, buffer, 10)
    operator.read(36, buffer, 2)
    operator.read(2, buffer, 4)
    operator.write(0, buffer, buffer.size)
    operator.read(0, buffer, 12)
    operator.read(47, buffer, 3)
    operator.read(45, buffer, 2)
    operator.read(47, buffer, 3)