Pytest class scope fixture for a parametrized test called once for each parameter

[alnet82]

fixt_finc fixture defined with class scope is being called twice - for every value of prm.
I expected it to be called only once. What am I missing here?

@pytest.fixture(scope='class')
def fixt_func(request, resource):
    print "fixt_func"

class TestA():
    @pytest.mark.parametrize('resource', ['x'], scope='class')
    @pytest.mark.parametrize('prm', ['a', 'b'])
    def test_a(self, prm, fixt_func)
        assert True