code: @Test public void bigIntegerSanityCheck_VariableCapacity(){
    BitArray a=new BitArray.VariableCapacity();
    BigInteger b=BigInteger.ZERO;
    a.set(64);
    b=b.setBit(64);
    assertEquals(bigIntegerToString(b),a.toString());
    a.set(1000000);
    b=b.setBit(1000000);
    assertEquals(bigIntegerToString(b),a.toString());
    a.shiftLeft(100);
    b=b.shiftLeft(100);
    assertEquals(bigIntegerToString(b),a.toString());
    a.set(0xF00D);
    b=b.setBit(0xF00D);
    a.set(0xBEEF);
    b=b.setBit(0xBEEF);
    a.set(0xDEAD);
    b=b.setBit(0xDEAD);
    assertEquals(bigIntegerToString(b),a.toString());
    a.shiftLeft(0xB0B);
    b=b.shiftLeft(0xB0B);
    assertEquals(bigIntegerToString(b),a.toString());
    a.toggle(64280);
    b=b.clearBit(64280);
    assertEquals(bigIntegerToString(b),a.toString());
  }
  