joinHelper(10, 20);
    joinHelper(10, 0, 20);
    joinHelper(0, 10, 20);
    joinHelper(10, 20, 0);
    joinHelper(10, 20, 1);
    joinHelper(1, 1, 1, 1, 1, 1, 1, 1);
    joinHelper(1, 0, 1, 0, 1, 0, 1, 0);
  }

  public void testOnlyOneOpen() throws Exception {
    ByteSource source = newByteSource(0, 50);
    int[] counter = new int[1];
    ByteSource checker =
        new ByteSource() {

    joinHelper(10, 20);
    joinHelper(10, 0, 20);
    joinHelper(0, 10, 20);
    joinHelper(10, 20, 0);
    joinHelper(10, 20, 1);
    joinHelper(1, 1, 1, 1, 1, 1, 1, 1);
    joinHelper(1, 0, 1, 0, 1, 0, 1, 0);
  }

  public void testOnlyOneOpen() throws Exception {
    ByteSource source = newByteSource(0, 50);
    int[] counter = new int[1];
    ByteSource checker =
        new ByteSource() {

        // P-node (01)
        System.arraycopy("PNODE           ".getBytes("US-ASCII"), 0, src, srcIndex + 19, 16);
        src[srcIndex + 34] = 0x00;
        src[srcIndex + 35] = 0x24; // 00100100 - P-node, active

        // M-node (10)
        System.arraycopy("MNODE           ".getBytes("US-ASCII"), 0, src, srcIndex + 37, 16);
        src[srcIndex + 52] = 0x00;

    }

    @Test
    @DisplayName("Should check capability correctly")
    void testHaveCapability() throws Exception {
        // Given
        setPrivateField(response, "commonCapabilities", 0x2F); // 0010 1111

        // Then
        assertTrue(response.haveCapabilitiy(0x01)); // Has this bit
        assertTrue(response.haveCapabilitiy(0x0F)); // Has all these bits