final byte[] result = FileUtil.readBytes(emptyFile);
        assertThat(result.length, is(0));
    }

    /**
     * Test readBytes with null file throws exception
     */
    @Test
    public void testReadBytes_NullFile() {
        try {
            FileUtil.readBytes(null);
            fail("Expected IllegalArgumentException");

			n, err := rb.Read(buf[:readRng.Intn(len(buf))])
			readBytes += n
			read.Write(buf[:n])
			debugln("READ 1\t", n, readBytes)
			if err != nil {
				readErr = err
				break
			}

			// ReadByte
			b, err := rb.ReadByte()
			if err != nil {
				readErr = err
				break
			}
			readBytes++
			read.Write([]byte{b})
			debugln("READ 2\t", 1, readBytes)

			// TryRead

	}

	// after successful read
	if _, err := b.ReadBytes('m'); err != nil {
		t.Fatalf("ReadBytes: %v", err)
	}
	if err := b.UnreadByte(); err != nil {
		t.Fatalf("UnreadByte: %v", err)
	}
	c, err := b.ReadByte()
	if err != nil {
		t.Fatalf("ReadByte: %v", err)
	}
	if c != 'm' {
		t.Errorf("ReadByte = %q; want %q", c, 'm')
	}
}

     * @return A byte array containing the contents of the file.
     * @throws IORuntimeException if the file is larger than {@value #MAX_BUF_SIZE} bytes
     */
    public static byte[] readBytes(final File file) {
        return readBytes(file, MAX_BUF_SIZE);
    }

    /**
     * Reads the contents of a file into a byte array and returns it with a custom size limit.
     * <p>

            readParams.setAccessible(true);
            readParams.invoke(cancel, buffer, 0);

            Method readBytes = SmbComNtCancel.class.getDeclaredMethod("readBytesWireFormat", byte[].class, int.class);
            readBytes.setAccessible(true);
            readBytes.invoke(cancel, buffer, 0);

            // Then - buffer should remain unchanged
            assertArrayEquals(originalBuffer, buffer);

	if b.off > 0 {
		b.off--
	}
	return nil
}

// ReadBytes reads until the first occurrence of delim in the input,
// returning a slice containing the data up to and including the delimiter.
// If ReadBytes encounters an error before finding a delimiter,
// it returns the data read before the error and the error itself (often [io.EOF]).
// ReadBytes returns err != nil if and only if the returned data does not end in
// delim.

              readBytesDelivered = readBuffer.read(sink, minOf(byteCount, readBuffer.size))
              readBytes.update(total = readBytesDelivered)

              val unacknowledgedBytesRead = readBytes.unacknowledged
              if (errorExceptionToDeliver == null &&
                unacknowledgedBytesRead >= connection.okHttpSettings.initialWindowSize / 2
              ) {

	totalLen += len(frag)
	return fullBuffers, frag, totalLen, err
}

// ReadBytes reads until the first occurrence of delim in the input,
// returning a slice containing the data up to and including the delimiter.
// If ReadBytes encounters an error before finding a delimiter,
// it returns the data read before the error and the error itself (often io.EOF).
// ReadBytes returns err != nil if and only if the returned data does not end in
// delim.

        assertNotNull(readParameterWords);

        Method readBytes = clazz.getDeclaredMethod("readBytesWireFormat", byte[].class, int.class);
        assertNotNull(readBytes);

        Method toString = clazz.getDeclaredMethod("toString");
        assertNotNull(toString);
    }

    withLock {
      readBytes.update(total = read)
      val readBytesToAcknowledge = readBytes.unacknowledged
      if (readBytesToAcknowledge >= okHttpSettings.initialWindowSize / 2) {
        writeWindowUpdateLater(0, readBytesToAcknowledge)
        readBytes.update(acknowledged = readBytesToAcknowledge)
      }
      flowControlListener.receivingConnectionWindowChanged(readBytes)
    }
  }

  /**