Scala Bitsets are sets of non-negative integers which are represented as variable-size arrays of bits packed into 64-bit words. The ++[B](that: GenTraversableOnce[B])
method is utilised create a bitset containing the elements from the left hand operand followed by the elements from the right hand operand.
Method Definition: def ++[B](that: GenTraversableOnce[B])
Return Type: It returns a new bitset which contains all elements of this bitset.
Set(0, 1, a, 2, B, 3)
Set(0, 1, A, 2, 3)