How to use the manticore.ethereum.plugins.FilterFunctions function in manticore

def __run_manticore(self, trace):
        self.print('[.] Running Manticore')

        consts = ManticoreConfig.get_group('core')
        consts.procs = self.procs

        output_path = self.__create_output_path()
        manticore = ManticoreEVM(workspace_url=output_path)

        if self.force_loop_limit:
            loop_delimiter = LoopDepthLimiter(loop_count_threshold=self.loop_limit)
            manticore.register_plugin(loop_delimiter)

        if self.avoid_constant_txs:
            filter_nohuman_constants = FilterFunctions(regexp=r'.*', depth='human', mutability='constant', include=False)
            manticore.register_plugin(filter_nohuman_constants)

        self.print('[...] Creating user accounts')
        for num in range(0, self.amount_user_accounts):
            account_name = 'user_account_' + str(num)
            manticore.create_account(balance=self.user_initial_balance, name=account_name)

        self.print('[...] Creating a contract and its library dependencies')
        with open(self.contract_path, 'r') as contract_file:
            source_code = contract_file.read()
        try:
            contract_account = manticore.solidity_create_contract(source_code,
                                                                  owner=manticore.get_account('user_account_0'),
                                                                  args=self.contract_args,
                                                                  contract_name=self.contract_name)
        except: