code: func (vector *BitVector) Set(bit byte, index int) {
  	vector.indexAssert(index)
  	byteIndex := uint32(index >> 3)
  	byteOffset := uint32(index % 8)
  
  	oldByte := vector.data[byteIndex]
  
  	var newByte byte
  	if bit == 1 {
  		// turn on the byteOffset'th bit
  		newByte = oldByte | 1<<byteOffset
  	} else {
  		// turn off the byteOffset'th bit
  		removeMask := byte(^(1 << byteOffset))
  		newByte = oldByte & removeMask
  	}
  	vector.data[byteIndex] = newByte
  }
docs: // Set changes the bit in the ith index of the bit vector to the value specified in
  // bit.