[Python] TypeError: __init__() takes at most 2 arguments (4 given)

i got error message when trying to run the test of django this is my code for the model file

class MountPoint(models.Model):
name = models.CharField(max_length=100)
backend = models.CharField(max_length=200,default=DEFAULT_BACKEND)
path = models.CharField(max_length=300)

def __unicode__(self):
return self.name


and here is the class i put in test

class MountPoint(TestCase):
def create_mountpoint(self):
name = "test"
backend = "test"
path = user_root
return MountPoint(name, backend, path)

def test_mountpoint_creation(self):
m = self.create_mountpoint()
self.assertTrue(isinstance(m, MountPoint))
self.assertEqual(m.__unicode(), m.name)


and the error message i got is below. it said i have more inputs than expected.

Traceback (most recent call last):
File "/Users/xihui/Documents/WebProgramming/django/ece264site/filesystem/tests.py", line 18, in test_mountpoint_creation
m = self.create_mountpoint()
File "/Users/xihui/Documents/WebProgramming/django/ece264site/filesystem/tests.py", line 15, in create_mountpoint
return MountPoint(name, backend, path)
TypeError: __init__() takes at most 2 arguments (4 given)

----------------------------------------------------------------------
Ran 1 test in 0.009s

FAILED (errors=1)

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