[Enhancement] Extension Point to extend `get_data_from_source` for all readers

[Noordsestern]

Hi,

i have a project with CSV reader (generic and specific), XLSX Reader and potentially JSON soon. As we have mass data being pumped threw RFW test cases, I would like to modify the test data on the fly, for instance limiting the number of rows processed by data driver to 10 (as example) when a specific variable is set..

Currently I implement a CustomReader for each datadriver reader inheriting the original reader:

• class LimitedGenericCsvReader(genericCsvReader):
• class LimitedCsvReader(csvReader):
• class LimitedXlsxReader(xlsxReader):
• ...

All these reader override get_data_from_source and return only the first i.e. 10 test cases of the data source.

Now instead of asking for another attribue for DataDriver, I thought maybe, it would be more convenient to provide some kind of extension point, where users could manipulate the test data.