How can I create a subclass of XlsxWriter?

[aquerci]

I just tried to write my custom method "write_table" in a custom subclass of "Worksheet" (WorksheetPlus). Below my code:

from xlsxwriter.worksheet import Worksheet

class WorksheetPlus(Worksheet):
    # custom method:     
    def write_table(self, info, row, column):
        for dic in info:
            y = column
            for key in dic:
                self.write(row, y, dic[key])
                y += 1
            row += 1
        
# test:
if __name__ == "__main__":
    from xlsxwriter.workbook import Workbook
    info = [{1:1, 2:2, 3:3, 4:4, 5:5}, {1:11, 2:22, 3:33, 4:444, 5:55}]
    obj_wb = Workbook("ciao.xlsx")
    obj_ws = obj_wb.add_worksheet("FIRST")
    obj_ws.write_table(info, 0, 0) #  why this statement doesn't work?

Unfortunately if I test this code, it doesn't work:

λ python WorksheetPlus.py

Traceback (most recent call last):
File "WorksheetPlus.py", line 22, in <module>
obj_ws.write_table(info, 0, 0) # come mai non funziona?
AttributeError: 'Worksheet' object has no attribute 'write_table' <------------- !!!

Why is not my custom method an attribute of "Worksheet" object? can you help me to fix my code?