import type TreeNode from '../../../utils/dataStructures/tree';
/**
 * A function that dump a tree structure into multidimensional array. That structure is
 * later processed by header renderers to modify TH elements to achieve a proper
 * DOM structure.
 *
 * That structure contains settings object for every TH element generated by Walkontable.
 * The matrix operates on visual column index.
 *
 * Output example:
 *   [
 *     [
 *       { label: 'A1', colspan: 2, origColspan: 2, isHidden: false, ... },
 *       { label: '', colspan: 1, origColspan: 1, isHidden: true, ... },
 *       { label: '', colspan: 1, origColspan: 1, isHidden: false, ... },
 *     ],
 *     [
 *       { label: 'true', colspan: 1, origColspan: 1, isHidden: false, ... },
 *       { label: 'B2', colspan: 1, origColspan: 1, isHidden: false, ... },
 *       { label: '4', colspan: 1, origColspan: 1, isHidden: false, ... },
 *     ],
 *     [
 *       { label: '', colspan: 1, origColspan: 1, isHidden: false, ... },
 *       { label: '', colspan: 1, origColspan: 1, isHidden: false, ... },
 *       { label: '', colspan: 1, origColspan: 1, isHidden: false, ... },
 *     ],
 *   ]
 *
 * @param {TreeNode[]} headerRoots An array of root nodes.
 * @returns {Array[]}
 */
export declare function generateMatrix(headerRoots: TreeNode[]): Record<string, unknown>[][];