code: def axis(chart_2d):
      # Test properties, using the y axis of a 2D chart
      chart_2d.line([0, 1], [1, 10])
      chart_2d.show()
      return chart_2d.y_axis
  
imports: import itertools
  import platform
  import weakref
  import numpy
  import pytest
  from vtkmodules.vtkRenderingContext2D import vtkPen
  import pyvista
  from pyvista import examples
  from pyvista.plotting import charts
  from pyvista.plotting.colors import COLOR_SCHEMES
label_desc: Use image node_id 16 for calling a global function with example usage: axis(chart_2d) and returns: chart_2d