Strange dotted line in Cocos2d / Python

Question

I'm trying to create a single straight line using Cocos2d with Python. Why in this code, I get a random dotted line?

import cocos
from cocos.director import director
from cocos import draw


class TestLayer(cocos.layer.Layer):
    def __init__(self):
        super().__init__()
        line = draw.Line((0, 0), (550, 450), (255, 255, 255, 255))
        self.add(line)


def main():
    director.init()
    test_layer = TestLayer()
    main_scene = cocos.scene.Scene(test_layer)
    director.run(main_scene)


if __name__ == '__main__':
    main()

Here a zoomed portion: