old_contents: from django.template import loader
  import utils
  
  from regulations.generator.layers.base import SearchReplaceLayer
  
  
  class ExternalCitationLayer(SearchReplaceLayer):
      shorthand = 'external'
      data_source = 'external-citations'
  
      def __init__(self, layer):
          self.layer = layer
          self.template = loader.get_template(
              'regulations/layers/external_citation.html')
  
      def replacements_for(self, text, data):
          yield utils.render_template(self.template, data)
  
new_contents: from django.template import loader
  
  from regulations.generator.layers import utils
  from regulations.generator.layers.base import SearchReplaceLayer
  
  
  class ExternalCitationLayer(SearchReplaceLayer):
      shorthand = 'external'
      data_source = 'external-citations'
  
      def __init__(self, layer):
          self.layer = layer
          self.template = loader.get_template(
              'regulations/layers/external_citation.html')
  
      def replacements_for(self, text, data):
          yield utils.render_template(self.template, data)
  
subject: Make external citations Python3 compatible