docs: async def rank(self) -> Optional[float]:
          """
          If there is a text layer inside the request, try to find a matching
          text in the specified intent.
          """
  
          if not self.request.has_layer(l.RawText):
              return
  
          tl = self.request.get_layer(l.RawText)
          matcher = Matcher([
              tuple(Trigram(y) for y in x)
              for x in await self.intent.strings(self.request)
          ])
  
          return matcher % Trigram(tl.text)