old_contents: """
  Contains slide show exporter
  """
  
  #-----------------------------------------------------------------------------
  # Copyright (c) 2013, 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
  #-----------------------------------------------------------------------------
  
  from IPython.utils.traitlets import Unicode
  
  from IPython.nbconvert import preprocessors
  from IPython.config import Config
  
  from .templateexporter import TemplateExporter
  
  #-----------------------------------------------------------------------------
  # Classes
  #-----------------------------------------------------------------------------
  
  class SlidesExporter(TemplateExporter):
      """
      Exports slides
      """
      
      file_extension = Unicode(
          'slides.html', config=True, 
          help="Extension of the file that should be written to disk"
          )
  
      default_template = Unicode('reveal', config=True, help="""Template of the 
          data format to use.  I.E. 'reveal'""")
  
      @property
      def default_config(self):
          c = Config({
              'CSSHTMLHeaderPreprocessor':{
                  'enabled':True
                  },
              'RevealHelpPreprocessor':{
                  'enabled':True,
                  },                
              })
          c.merge(super(SlidesExporter,self).default_config)
          return c
  
new_contents: """
  Contains slide show exporter
  """
  
  #-----------------------------------------------------------------------------
  # Copyright (c) 2013, 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
  #-----------------------------------------------------------------------------
  
  from IPython.utils.traitlets import Unicode
  
  from IPython.nbconvert import preprocessors
  from IPython.config import Config
  
  from .templateexporter import TemplateExporter
  
  #-----------------------------------------------------------------------------
  # Classes
  #-----------------------------------------------------------------------------
  
  class SlidesExporter(TemplateExporter):
      """
      Exports slides
      """
      
      file_extension = Unicode(
          'slides.html', config=True, 
          help="Extension of the file that should be written to disk"
          )
  
      default_template = Unicode('reveal', config=True, help="""Template of the 
          data format to use.  I.E. 'reveal'""")
  
      @property
      def default_config(self):
          c = Config({
              'CSSHTMLHeaderPreprocessor':{
                  'enabled':True
                  },
              'RevealHelpPreprocessor':{
                  'enabled':True,
                  },                
              'HighlightMagicsPreprocessor': {
                  'enabled':True
                  }
              })
          c.merge(super(SlidesExporter,self).default_config)
          return c
  
subject: Enable HighlightMagics in slides exporter