1. override
void debugFillDescription(List<String> description)

Accumulates a list of strings describing the current node's fields, one field per string. Subclasses should override this to have their information included in toStringDeep.

Source 

@override
void debugFillDescription(List<String> description) {
  super.debugFillDescription(description);
  if (border != null)
    description.add('border: $border');
  if (_columnWidths.isNotEmpty)
    description.add('specified column widths: $_columnWidths');
  description.add('default column width: $defaultColumnWidth');
  description.add('table size: $columns\u00D7$rows');
  if (!needsLayout) {
    description.add('column offsets: ${ _columnLefts ?? "unknown" }');
    description.add('row offsets: ${ _rowTops ?? "unknown" }');
  }
}