TST: Add test case for groupby where by column contains values with same starting value (#46721)
TST: Add test case for groupby where by column contains values with same starting value (#46721)

GH29635

Co-authored-by: Mateusz <6f14f9923cf3b31a9c621f96a93cc25623f98c70@gmail.com>
pandas-dev/pandas,datapythonista/pandas,datapythonista/pandas,pandas-dev/pandas,datapythonista/pandas,pandas-dev/pandas,datapythonista/pandas,pandas-dev/pandas