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() {

* `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()

    }

    @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];

            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);

      int off = (int) expectedSize - remaining;
      int read = in.read(bytes, off, remaining);
      if (read == -1) {
        // end of stream before reading expectedSize bytes
        // just return the bytes read so far
        return Arrays.copyOf(bytes, off);
      }
      remaining -= read;
    }

    // bytes is now full
    int b = in.read();
    if (b == -1) {
      return bytes;
    }

		t.Errorf("r.Len(): got %d, want %d", got, want)
	}
	if n, err := r.Read(make([]byte, 10)); err != nil || n != 10 {
		t.Errorf("Read failed: read %d %v", n, err)
	}
	if got, want := r.Len(), 1; got != want {
		t.Errorf("r.Len(): got %d, want %d", got, want)
	}
	if n, err := r.Read(make([]byte, 1)); err != nil || n != 1 {
		t.Errorf("Read failed: read %d %v; want 1, nil", n, err)
	}
	if got, want := r.Len(), 0; got != want {

     * @param len length of data to read
     * @return number of bytes read
     */
    protected abstract int readSetupWireFormat(byte[] buffer, int bufferIndex, int len);

    /**
     * Reads parameters from wire format
     * @param buffer source buffer
     * @param bufferIndex starting index in source buffer
     * @param len length of data to read
     * @return number of bytes read

    assertEquals(0, ticker.read());
    assertEquals(10, ticker.read());
    assertEquals(20, ticker.read());
  }

  public void testAutoIncrementStep_millis() {
    FakeTicker ticker = new FakeTicker().setAutoIncrementStep(1, MILLISECONDS);
    assertEquals(0, ticker.read());
    assertEquals(1000000, ticker.read());
    assertEquals(2000000, ticker.read());
  }

    }

    @Override
    public synchronized int read() throws IOException {
        if (read(tmp, 0, 1) < 0) {
            return -1;
        }
        return tmp[0] & 0xFF;
    }

    @Override
    public synchronized int read(final byte[] b) throws IOException {
        return read(b, 0, b.length);
    }

    /* This method will not return until len bytes have been read
     * or the stream has been closed.
     */