code: def test_no_pyplot():
      # tests pickle-ability of a figure not created with pyplot
      from matplotlib.backends.backend_pdf import FigureCanvasPdf
  
      fig = mfigure.Figure()
      _ = FigureCanvasPdf(fig)
      ax = fig.add_subplot(1, 1, 1)
      ax.plot([1, 2, 3], [1, 2, 3])
      pickle.dump(fig, BytesIO(), pickle.HIGHEST_PROTOCOL)
  
imports: from io import BytesIO
  import ast
  import pickle
  import pickletools
  import numpy
  import pytest
  import matplotlib
  from matplotlib import cm
  from matplotlib.testing import subprocess_run_helper
  from matplotlib.testing.decorators import check_figures_equal
  from matplotlib.dates import rrulewrapper
  from matplotlib.lines import VertexSelector
  import matplotlib.pyplot
  import matplotlib.transforms
  import matplotlib.figure
  from mpl_toolkits.axes_grid1 import parasite_axes
label_desc: Use image node_id 7 for calling a global function with example usage: test_no_pyplot() without return types