docs: @Override
    public CellType getCachedFormulaResultType() {
      if (formulaType) {
        if(contentsSupplier.getContent() == null || type == null) {
          return CellType.BLANK;
        } else if("n".equals(type)) {
          return CellType.NUMERIC;
        } else if("s".equals(type) || "inlineStr".equals(type) || "str".equals(type)) {
          return CellType.STRING;
        } else if("b".equals(type)) {
          return CellType.BOOLEAN;
        } else if("e".equals(type)) {
          return CellType.ERROR;
        } else {
          throw new UnsupportedOperationException("Unsupported cell type '" + type + "'");
        }
      } else  {
        throw new IllegalStateException("Only formula cells have cached results");
      }
    }