Indexing with a cell address string maps to a cell object Special keys start with '!'
Optional!autofilterAutoFilter info
Optional!colsColumn Info
Optional!dataDense-mode worksheets store data in an array of arrays
Cells are accessed with sheet['!data'][R][C] (where R and C are 0-indexed)
Optional!marginsPage Margins
Optional!mergesMerge Ranges
Optional!protectWorksheet Protection info
Optional!refSheet Range (A1-style)
Optional!rowsRow Info
Optional!typeSheet type
Worksheet Object