parameters: (self, func)
return_statement: return token
docstring: Registers `func` and returns a unique token for this entry.
docstring_summary: Registers `func` and returns a unique token for this entry.
docstring_tokens: Registers func and returns a unique token for this entry .
function: def insert(self, func):
      """Registers `func` and returns a unique token for this entry."""
      token = self._next_unique_token()
      self._funcs[token] = func
      return token
function_tokens: def insert ( self , func ) : token = self . _next_unique_token ( ) self . _funcs [ token ] = func return token