code: def compile_template(instance, template, additionnal_context=None):
      
      py3o_context = get_compilation_context(instance)
  
      if additionnal_context is not None:
          py3o_context.update(additionnal_context)
  
      output_doc = StringIO()
  
      odt_builder = Template(template, output_doc)
      odt_builder.render(py3o_context)
  
      return output_doc
docs: Fill the given template with the instance's datas and return the odt file
  
      For every instance class, common values are also inserted in the context
      dict (and so can be used) :
  
          * config values
  
      :param obj instance: the instance of a model (like Userdatas, Company)
      :param template: the template object to use
      :param dict additionnal_context: A dict containing datas we'd like to add to
      the py3o compilation template
      :return: a stringIO object filled with the resulting odt's informations