code: def documentation(self, add_to=None, version=None, prefix="", base_url="", url=""):
          
          doc = OrderedDict() if add_to is None else add_to
  
          usage = self.interface.spec.__doc__
          if usage:
              doc['usage'] = usage
  
          for example in self.examples:
              example_text = "{0}{1}{2}{3}".format(prefix, base_url, '/v{0}'.format(version) if version else '', url)
              if isinstance(example, str):
                  example_text += "?{0}".format(example)
              doc_examples = doc.setdefault('examples', [])
              if not example_text in doc_examples:
                  doc_examples.append(example_text)
  
          doc = super().documentation(doc)
  
          if getattr(self, 'output_doc', ''):
              doc['outputs']['type'] = self.output_doc
  
          return doc
docs: Returns the documentation specific to an HTTP interface