code: def __fix_context(context):
      
  
      COPY_LISTS = ('script_files', 'css_files',)
  
      for attr in COPY_LISTS:
          if attr in context:
              context[attr] = context[attr][:]
  
      return context
docs: Return a new context dict based on original context.
  
      The new context will be a copy of the original, and some mutable
      members (such as script and css files) will also be copied to
      prevent polluting shared context.