docstr: %pylab works on engines
code: def test_px_pylab(self):
      """%pylab works on engines"""
      pytest.importorskip("matplotlib")
      ip = get_ipython()
      v = self.client[-1]
      v.block = True
      v.activate()
  
      with capture_output() as io:
          ip.run_line_magic("px", "%pylab inline")
  
      assert (
          "Populating the interactive namespace from numpy and matplotlib"
          in io.stdout
      )
  
      with capture_output(display=False) as io:
          ip.run_line_magic("px", "plot(rand(100))")
      assert "Out[" in io.stdout
      assert "matplotlib.lines" in io.stdout
  
imports: import re
  import signal
  import sys
  import time
  import pytest
  from IPython import get_ipython
  from IPython.utils.io import capture_output
  import ipyparallel
  from ipyparallel import AsyncResult
  from .clienttest import ClusterTestCase, generate_output, raises_remote
label_desc: Use image node_id 17 for calling the TestParallelMagics obj's underlying member method code with example usage: obj.test_px_pylab() without return types