testing class init method with unittest

I'm learning how to use unittest in python. I have a class that receives a pandas dataframe in it's init method.

class GenericClass:

    def __init__(self, data):
        
        if not (isinstance(data, pd.DataFrame) or isinstance(data, pd.Series)):
            raise ValueError(f'The object {data} must be a pd.DataFrame or a pd.Series')
        
        self.data = data

I've created a file called test.py. And in this file i'll test the methods of GenericClass.

import unittest
from file import GenericClass

class TestHistan(unittest.TestCase):

    def test_input(self):
        # no idea on how to implement this

My question is, how do i make a test function that tests the inputs passed on the init method of the generic Class?