Function read_xlsx_with 

pub fn read_xlsx_with(
    bytes: &[u8],
    known: &dyn Fn(&str) -> bool,
) -> Result<(Workbook, ReadReport), IoError>

read_xlsx, and opens formulas from Google Sheets’ XLSX export as the formulas written in Google Sheets (#2871).

Google writes a formula that uses a function it thinks Excel lacks as IFERROR(__xludf.DUMMYFUNCTION("<formula, quotes doubled>"),<cached value>); Excel shows the cached value. A cell formula holding that wrapper, whole or inside a larger formula, is read as the formula inside when it parses and known says GridCraft calculates every function it calls. Otherwise (a Google-only function such as GOOGLETRANSLATE, inner text that doesn’t parse, or nesting past the parser’s limit) the wrapper stays, so the cell keeps showing the cached value as in Excel. known is passed in because this crate doesn’t depend on the function library.