new_contents: """Tests for debugging machinery.
  """
  #-----------------------------------------------------------------------------
  #  Copyright (c) 2012, The IPython Development Team.
  #
  #  Distributed under the terms of the Modified BSD License.
  #
  #  The full license is in the file COPYING.txt, distributed with this software.
  #-----------------------------------------------------------------------------
  
  #-----------------------------------------------------------------------------
  # Imports
  #-----------------------------------------------------------------------------
  
  # third-party
  import nose.tools as nt
  
  # Our own
  from IPython.core import debugger
  
  #-----------------------------------------------------------------------------
  # Tests
  #-----------------------------------------------------------------------------
  
  def test_longer_repr():
      from repr import repr as trepr
      
      a = '1234567890'* 7
      ar = "'1234567890123456789012345678901234567890123456789012345678901234567890'"
      a_trunc = "'123456789012...8901234567890'"
      nt.assert_equals(trepr(a), a_trunc)
      # The creation of our tracer modifies the repr module's repr function
      # in-place, since that global is used directly by the stdlib's pdb module.
      t = debugger.Tracer()
      nt.assert_equals(trepr(a), ar)
  
subject: Add simple test for modified repr as per review.