code: def run_main(
      self, seconds_per_increment=1.0, switches=None, timer=None
  ):
      if timer is None:
          timer = FakeTimer(seconds_per_increment=seconds_per_increment)
      if switches is None:
          args = []
      else:
          args = switches[:]
      args.append(self.fake_stmt)
      # timeit.main() modifies sys.path, so save and restore it.
      orig_sys_path = sys.path[:]
      with captured_stdout() as s:
          timeit.main(args=args, _wrap_timer=timer.wrap_timer)
      sys.path[:] = orig_sys_path[:]
      return s.getvalue()
  
imports: import timeit
  import unittest
  import sys
  import io
  from textwrap import dedent
  from test.support import captured_stdout
  from test.support import captured_stderr
label_desc: Use image node_id 30 for calling the TestTimeit obj's underlying member method code with example usage: obj.run_main(seconds_per_increment, switches, timer) and returns: s