static final int tableSizeFor(int cap){
  int n=cap - 1;
  n|=n >>> 1;
  n|=n >>> 2;
  n|=n >>> 4;
  n|=n >>> 8;
  n|=n >>> 16;
  return (n < 0) ? 1 : (n >= MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : n + 1;
}

static final int tableSizeFor ( int cap ) { int n = cap - 1 ; n |= n > > > 1 ; n |= n > > > 2 ; n |= n > > > 4 ; n |= n > > > 8 ; n |= n > > > 16 ; return ( n < 0 ) ? 1 : ( n >= MAXIMUM_CAPACITY ) ? MAXIMUM_CAPACITY : n + 1 ; }
returns a power of two size for the given target capacity .
