old_contents: """Module containing a transformer that converts outputs in the notebook from 
  one format to another.
  """
  #-----------------------------------------------------------------------------
  # 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 .base import Transformer
  from IPython.utils.traitlets import Unicode
  
  #-----------------------------------------------------------------------------
  # Classes
  #-----------------------------------------------------------------------------
  
  class ConvertFiguresTransformer(Transformer):
      """
      Converts all of the outputs in a notebook from one format to another.
      """
  
      from_format = Unicode(config=True, help='Format the converter accepts')
      to_format = Unicode(config=True, help='Format the converter writes')
  
      def __init__(self, **kw):
          """
          Public constructor
          """
          super(ConvertFiguresTransformer, self).__init__(**kw)
  
  
      def convert_figure(self, data_format, data):
          raise NotImplementedError()
  
  
      def transform_cell(self, cell, resources, cell_index):
          """
          Apply a transformation on each cell,
          
          See base.py
          """
  
          #Loop through all of the datatypes of the outputs in the cell.
          for index, cell_out in enumerate(cell.get('outputs', [])):
              for data_type, data in cell_out.items():
  
                  #Get the name of the file exported by the extract figure 
                  #transformer.  Do not try to convert the figure if the extract
                  #fig transformer hasn't touched it
                  filename = cell_out.get(data_type + '_filename', None)
                  if filename:
                      figure_name = filename[:filename.rfind('.')]
                      self._convert_figure(cell_out, figure_name, resources, data_type, data)
          return cell, resources
  
  
      def _convert_figure(self, cell_out, resources, figure_name, data_type, data):
          """
          Convert a figure and output the results to the cell output
          """
  
          if not self.to_format in cell_out:
              if data_type == self.from_format:
                  filename = figure_name + '.' + self.to_format
                  if filename not in resources['figures']:
  
                      #On the cell, make the figure available via 
                      #   cell.outputs[i].pdf_filename  ... etc (PDF in example)
                      cell_out[self.to_format + '_filename'] = filename
  
                      #In the resources, make the figure available via
                      #   resources['figures']['filename'] = data
                      resources['figures'][filename] = self.convert_figure(data_type, data)
  
new_contents: """Module containing a transformer that converts outputs in the notebook from 
  one format to another.
  """
  #-----------------------------------------------------------------------------
  # 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 .base import Transformer
  from IPython.utils.traitlets import Unicode
  
  #-----------------------------------------------------------------------------
  # Classes
  #-----------------------------------------------------------------------------
  
  class ConvertFiguresTransformer(Transformer):
      """
      Converts all of the outputs in a notebook from one format to another.
      """
  
      from_format = Unicode(config=True, help='Format the converter accepts')
      to_format = Unicode(config=True, help='Format the converter writes')
  
      def __init__(self, **kw):
          """
          Public constructor
          """
          super(ConvertFiguresTransformer, self).__init__(**kw)
  
  
      def convert_figure(self, data_format, data):
          raise NotImplementedError()
  
  
      def transform_cell(self, cell, resources, cell_index):
          """
          Apply a transformation on each cell,
          
          See base.py
          """
  
          #Loop through all of the datatypes of the outputs in the cell.
          for index, cell_out in enumerate(cell.get('outputs', [])):
              for data_type, data in cell_out.items():
                  # this must run *before* extract figures,
                  # so figure_name and filename do not exist
                  self._convert_figure(cell_out, resources, data_type, data)
          return cell, resources
  
  
      def _convert_figure(self, cell_out, resources, data_type, data):
          """
          Convert a figure and output the results to the cell output
          """
          if not self.to_format in cell_out and data_type == self.from_format:
              data = self.convert_figure(data_type, data)
              cell_out[self.to_format] = data
  
subject: simplify ConvertFiguresTransformer