Sequence.TwoD
A TwoD Sequence holds a two dimensional array, similar to that of drawdown, however, storing numbers instead of Cell objects. This offers a flexible format for building drafts. For example, OneD objects can be added to TwoD objects as either rows/wefts or columns/warps.
src/app/core/model/sequence.js
const seq: Sequence.TwoD = new Sequence.TwoD();