code: def _TryToStartNextPathspec(self):
      
  
      # Nothing to do here.
      if self.state.maximum_pending_files <= len(self.state.pending_files):
        return
  
      if self.state.maximum_pending_files <= len(self.state.pending_hashes):
        return
  
      try:
        index = self.state.next_pathspec_to_start
        pathspec = self.state.indexed_pathspecs[index]
        self.state.next_pathspec_to_start = index + 1
      except IndexError:
        # We did all the pathspecs, nothing left to do here.
        return
  
      # Add the file tracker to the pending hashes list where it waits until the
      # hash comes back.
      self.state.pending_hashes[index] = {"index": index}
  
      # First state the file, then hash the file.
  
      # TODO(hanuszczak): Support for old clients ends on 2021-01-01.
      # This conditional should be removed after that date.
      if self.client_version >= 3221:
        stub = server_stubs.GetFileStat
        request = rdf_client_action.GetFileStatRequest(pathspec=pathspec)
        request_name = "GetFileStat"
      else:
        stub = server_stubs.StatFile
        request = rdf_client_action.ListDirRequest(pathspec=pathspec)
        request_name = "StatFile"
  
      self.CallClient(
          stub,
          request,
          next_state="StoreStat",
          request_data=dict(index=index, request_name=request_name))
  
      request = rdf_client_action.FingerprintRequest(
          pathspec=pathspec, max_filesize=self.state.file_size)
      request.AddRequest(
          fp_type=rdf_client_action.FingerprintTuple.Type.FPT_GENERIC,
          hashers=[
              rdf_client_action.FingerprintTuple.HashType.MD5,
              rdf_client_action.FingerprintTuple.HashType.SHA1,
              rdf_client_action.FingerprintTuple.HashType.SHA256
          ])
  
      self.CallClient(
          server_stubs.HashFile,
          request,
          next_state="ReceiveFileHash",
          request_data=dict(index=index))
docs: Try to schedule the next pathspec if there is enough capacity.