code: def test_labs_empty():
      spec = gg.labs()
      assert spec.as_dict()["feature-list"] == []
  
imports: import pytest
  import lets_plot
  from lets_plot.plot.core import FeatureSpec
  from lets_plot.plot.core import FeatureSpecArray
  from lets_plot.plot.scale import _scale
label_desc: Use image node_id 3 for calling a global function with example usage: test_labs_empty() without return types