code: def test_plot_ax():
      fig = plt.figure()
      ax = fig.add_subplot(111, projection="3d")
      geo = plot.plot(data, ax=ax, show=False)
      assert isinstance(geo, DataGeometry)
  
imports: import pytest
  import numpy
  import matplotlib
  import matplotlib.pyplot
  from hypertools.plot import plot
  from hypertools.tools.reduce import reduce
  from hypertools.tools.load import load
  from hypertools.datageometry import DataGeometry
label_desc: Use image node_id 19 for calling a global function with example usage: test_plot_ax() without return types