text: import builtins
  import subprocess
  import sys
  
  import matplotlib
  from matplotlib.cbook import dedent
  
  
  def test_simple():
      assert 1 + 1 == 2
  
  
  def test_override_builtins():
      import pylab
  
      ok_to_override = {
          '__name__',
          '__doc__',
          '__package__',
          '__loader__',
          '__spec__',
          'any',
          'all',
          'sum',
          'divmod'
      }
      overridden = False
      for key in dir(pylab):
          if key in dir(builtins):
              if (getattr(pylab, key) != getattr(builtins, key) and
                      key not in ok_to_override):
                  print("'%s' was overridden in globals()." % key)
                  overridden = True
  
      assert not overridden
  
  
  def test_lazy_imports():
      source = dedent("""
      import sys
  
      import matplotlib.figure
      import matplotlib.backend_bases
      import matplotlib.pyplot
  
      assert 'matplotlib._png' not in sys.modules
      assert 'matplotlib._tri' not in sys.modules
      assert 'matplotlib._qhull' not in sys.modules
      assert 'matplotlib._contour' not in sys.modules
      assert 'urllib.request' not in sys.modules
      """)
  
      subprocess.check_call([
          sys.executable,
          '-c',
          source
      ])
  