[Continuations:005]: Move a Continuation

It SHALL be possible to move a continuation by dragging it upwards or downwards to a new location inside the operand.

The new location will be constrained, for continuation at begin of the operand by the top border of the operand, and for continuations at the end of the operand, by the bottom border of the operand.

No changes in the fragment order will occur.

Any existing fragment located in the operand, following the insertion point will be shifted up or down by an equivalent distance. The operand and the combined fragment will be resized accordingly.

The continuation will cover all the lifelines covered by the enclosing operand.