new_contents: import os
  import sys
  sys.path.append(os.path.join(os.path.dirname(__file__), ".."))
  import unittest
  import time
  
  from test_util import ScanPointGeneratorTest
  from scanpointgenerator import CompoundGenerator
  from scanpointgenerator import LineGenerator
  from scanpointgenerator import SpiralGenerator
  from scanpointgenerator import Excluder
  from scanpointgenerator.rois import CircularROI
  from scanpointgenerator.mutators import FixedDurationMutator, RandomOffsetMutator
  
  class CompoundGeneratorPerformanceTest(ScanPointGeneratorTest):
      def test_200_million_time_constraint(self):
          start_time = time.time()
  
          s = SpiralGenerator(
              ["x", "y"], "mm", [0, 0], 6, 0.02,
              alternate_direction=True) # ~2e5 points
          z = LineGenerator("z", "mm", 0, 1, 100) #1e2 points
          w = LineGenerator("w", "mm", 0, 1, 10) #1e1 points
          r1 = CircularROI([-0.7, 4], 0.5)
          r2 = CircularROI([0.5, 0.5], 0.3)
          r3 = CircularROI([0.2, 4], 0.5)
          e1 = Excluder(r1, ["x", "y"])
          e2 = Excluder(r2, ["w", "z"])
          e3 = Excluder(r3, ["z", "y"])
          fm = FixedDurationMutator(0.1)
          om = RandomOffsetMutator(0, ["x", "y"], {"x":0.2, "y":0.2})
          g = CompoundGenerator([w, z, s], [e1, e3, e2], [fm, om])
          g.prepare() # g.num ~3e5
  
          end_time = time.time()
          #self.assertLess(end_time - start_time, 5)
          # TravisCI VMs are sometimes pretty weak
          # if this test becomes problematic then we'll just have to remove it
          self.assertLess(end_time - start_time, 12)
  
          # we dont care about this right now
          #start_time = time.time()
          #for p in g.iterator():
          #    pass
          #end_time = time.time()
          ## point objects are quite expensive to create
          #self.assertLess(end_time - start_time, 20)
  
  if __name__ == "__main__":
      unittest.main(verbosity=2)
  
subject: Add time-sensitive test for compound generator for a large scan.