Is vtkUnstructuredGrid part of vtkDataSet

I have a clipped data set called vtk_data. It is a vtkUnstructuredGrid type

print(vtk_data.GetDataInformation(0).GetDataClassName())
>> vtkUnstructuredGrid

When I check if it is ‘vtkDataSet’ it returns 0

vtk_data.GetDataInformation(0).IsA("vtkDataSet")
>> 0