/**
 * A function that normalizes user-defined settings into one predictable
 * structure. Currently, the developer can declare nested headers by passing
 * the following unstructured (and sometimes uncompleted) array.
 *   [
 *     [{ label: 'A1', colspan: 2 }],
 *     [{ label: true }, 'B2', 4],
 *     [],
 *   ]
 *
 * The normalization process equalizes the length of columns to each header
 * layers to the same length and generates object settings with a common shape.
 * So the above mentioned example will be normalized into this:
 *   [
 *     [
 *       { label: 'A1', colspan: 2, isHidden: false, ... },
 *       { label: '', colspan: 1, isHidden: true, ... },
 *       { label: '', colspan: 1, isHidden: false, ... },
 *     ],
 *     [
 *       { label: 'true', colspan: 1, isHidden: false, ... },
 *       { label: 'B2', colspan: 1, isHidden: false, ... },
 *       { label: '4', colspan: 1, isHidden: false, ... },
 *     ],
 *     [
 *       { label: '', colspan: 1, isHidden: false, ... },
 *       { label: '', colspan: 1, isHidden: false, ... },
 *       { label: '', colspan: 1, isHidden: false, ... },
 *     ],
 *   ]
 *
 * @param {Array[]} sourceSettings An array with defined nested headers settings.
 * @param {number} [columnsLimit=Infinity] A number of columns to which the structure
 *                                         will be trimmed. While trimming the colspan
 *                                         values are adjusted to preserve the original
 *                                         structure.
 * @returns {Array[]}
 */
export declare function normalizeSettings(sourceSettings: unknown[][], columnsLimit?: number): unknown[][];