func (b *BitSet) Clear(i uint) *BitSet {
	if i >= b.length {
		return b
	}
	b.set[i>>log2Uint64Size] &^= 1 << (i & (uint64Size - 1))
	return b
}
// Clear bit i to 0.
Clear bit i to 0.
// Clear bit i to 0 .
func (b *BitSet) Clear(i uint) *BitSet {
	if i >= b.length {
		return b
	}
	b.set[i>>log2Uint64Size] &^= 1 << (i & (uint64Size - 1))
	return b
}
func ( b * BitSet ) Clear ( i uint ) * BitSet { if i >= b . length { return b } b . set [ i >> log2Uint64Size ] &^= 1 << ( i & ( uint64Size - 1 ) ) return b }
Clear bit i to 0.
Clear bit i to 0 .