code: def add(self, handler):
          ''' Add a handler to the pipeline used to initialize new documents.
  
          Args:
              handler (Handler) : a handler for this Application to use to
                  process Documents
  
          '''
          self._handlers.append(handler)
  
          # make sure there is at most one static path
          static_paths = set(h.static_path() for h in self.handlers)
          static_paths.discard(None)
          if len(static_paths) > 1:
              raise RuntimeError("More than one static path requested for app: %r" % list(static_paths))
          elif len(static_paths) == 1:
              self._static_path = static_paths.pop()
          else:
              self._static_path = Nonf add(self, handler):
          ''' Add a handler to the pipeline used to initialize new documents.
  
          Args:
              handler (Handler) : a handler for this Application to use to
                  process Documents
  
          '''
          self._handlers.append(handler)
  
          # make sure there is at most one static path
          static_paths = set(h.static_path() for h in self.handlers)
          static_paths.discard(None)
          if len(static_paths) > 1:
              raise RuntimeError("More than one static path requested for app: %r" % list(static_paths))
          elif len(static_paths) == 1:
              self._static_path = static_paths.pop()
          else:
              self._static_path = None
docs: Add a handler to the pipeline used to initialize new documents.
  
          Args:
              handler (Handler) : a handler for this Application to use to
                  process Documents