code: def test_quiver_key_pivot():
      fig, ax = plt.subplots()
  
      u, v = np.mgrid[0 : 2 * np.pi : 10j, 0 : 2 * np.pi : 10j]
  
      q = ax.quiver(np.sin(u), np.cos(v))
      ax.set_xlim(-2, 11)
      ax.set_ylim(-2, 11)
      ax.quiverkey(q, 0.5, 1, 1, "N", labelpos="N")
      ax.quiverkey(q, 1, 0.5, 1, "E", labelpos="E")
      ax.quiverkey(q, 0.5, 0, 1, "S", labelpos="S")
      ax.quiverkey(q, 0, 0.5, 1, "W", labelpos="W")
  
imports: import platform
  import sys
  import numpy
  import pytest
  from matplotlib import pyplot
  from matplotlib.testing.decorators import image_comparison
label_desc: Use image node_id 12 for calling a global function with example usage: test_quiver_key_pivot() without return types