human
I wrote the below code

    class MyModel(Fittable1DModel, ):
        a = Parameter(default=1)
        b = Parameter(default=0, min=0, fixed=True)
        @staticmethod
        def evaluate(x, a, b):
            return ((x * a) + b)
    assert (MyModel.a.default == 1)
    assert (MyModel.b.default == 0)
    assert (MyModel.b.min == 0)
    assert (MyModel.b.bounds == (0, None))
    assert (MyModel.b.fixed is True)
    m = MyModel()
    assert (m.a.value == 1)
    assert (m.b.value == 0)
    assert (m.b.min == 0)
    assert (m.b.bounds == (0, None))
    assert (m.b.fixed is True)
    assert (m.bounds == {u'a': (None, None), u'b': (0, None)})
    assert (m.fixed == {u'a': False, u'b': True})
    m = MyModel(3, 4, bounds={u'a': (1, None), u'b': (2, None)}, fixed={u'a': True, u'b': False})
    assert (m.a.value == 3)
    assert (m.b.value == 4)
    assert (m.a.min == 1)
    assert (m.b.min == 2)
    assert (m.a.bounds == (1, None))
    assert (m.b.bounds == (2, None))
    assert (m.a.fixed is True)
    assert (m.b.fixed is False)
    assert (m.bounds == {u'a': (1, None), u'b': (2, None)})
    assert (m.fixed == {u'a': True, u'b': False})

What's a good function header?
 ... Here's a good function header?
assistant
#Here's a good function header.

def test_default_constraints():