code: def test_set_alpha():
      art = martist.Artist()
      with pytest.raises(
          TypeError, match="^alpha must be numeric or None"
      ):
          art.set_alpha("string")
      with pytest.raises(
          TypeError, match="^alpha must be numeric or None"
      ):
          art.set_alpha([1, 2, 3])
      with pytest.raises(ValueError, match="outside 0-1 range"):
          art.set_alpha(1.1)
      with pytest.raises(ValueError, match="outside 0-1 range"):
          art.set_alpha(np.nan)
  
imports: import io
  from itertools import chain
  import numpy
  import pytest
  import matplotlib.colors
  import matplotlib.pyplot
  import matplotlib.patches
  import matplotlib.lines
  import matplotlib.path
  import matplotlib.transforms
  import matplotlib.collections
  import matplotlib.artist
  import matplotlib.backend_bases
  import matplotlib
  from matplotlib.testing.decorators import check_figures_equal, image_comparison
label_desc: Use image node_id 14 for calling a global function with example usage: test_set_alpha() without return types