question: private void ensureCapacity ( int desiredLongCount ) { if ( desiredLongCount <= bits . length ) { return ; } int newLength = Math . max ( desiredLongCount , bits . length * 2 ) ; long [ ] newBits = new long [ newLength ] ; System . arraycopy ( bits , 0 , newBits , 0 , longCount ) ; this . bits = newBits ; }
target:  Ensures that our long[] can hold at least 64 * desiredLongCount bits.