'Write a blank cell with formatting to a worksheet cell. The blank
token is ignored and the format only is written to the cell.
Args:
row:         The cell row (zero indexed).
col:         The cell column (zero indexed).
blank:       Any value. It is ignored.
cell_format: An optional cell Format object.
Returns:
0:  Success.
-1: Row or column is out of worksheet bounds.'

@convert_cell_args
def write_blank(self, row, col, blank, cell_format=None):

    if (cell_format is None):
        return 0
    if self._check_dimensions(row, col):
        return (-1)
    if (self.constant_memory and (row > self.previous_row)):
        self._write_single_row(row)
    self.table[row][col] = cell_blank_tuple(cell_format)
    return 0
