code: def test_change_data(self):
      layer = Directions(start=(0.0, 0.0), end=(2.0, 2.0))
      layer.data = self.data_array
      assert layer.start == self.start
      assert layer.end == self.end
      assert layer.waypoints == self.waypoints
  
imports: import unittest
  import pytest
  import traitlets
  from ..directions import Directions, DEFAULT_STROKE_COLOR
label_desc: Use image node_id 5 for calling the DirectionsLayer obj's underlying member method code with example usage: obj.test_change_data() without return types