How to use the pydra.engine.helpers_state.remove_inp_from_splitter_rpn function in pydra

# removing elements that are connected to inner splitter
        # (they will be taken into account in hlpst.splits anyway)
        # _comb part will be used in prepare_states_combined_ind
        # TODO: need tests in test_Workflow.py
        elements_to_remove = []
        elements_to_remove_comb = []
        for name, (st, inp) in self.other_states.items():
            if (
                f"{self.name}.{inp}" in self.splitter_rpn
                and f"_{name}" in self.splitter_rpn_compact
            ):
                elements_to_remove.append(f"_{name}")
                if f"{self.name}.{inp}" not in self.combiner:
                    elements_to_remove_comb.append(f"_{name}")

        partial_rpn = hlpst.remove_inp_from_splitter_rpn(
            deepcopy(self.splitter_rpn_compact), elements_to_remove
        )
        values_out_pr, keys_out_pr = hlpst.splits(
            partial_rpn,
            self.inputs,
            inner_inputs=self.inner_inputs,
            cont_dim=self.cont_dim,
        )
        values_pr = list(values_out_pr)

        self.ind_l = values_pr
        self.keys = keys_out_pr
        self.states_ind = list(hlpst.iter_splits(values_pr, self.keys))
        self.keys_final = self.keys
        if self.combiner:
            self.prepare_states_combined_ind(elements_to_remove_comb)

def splitter_rpn_final(self):
        if self.combiner:
            _splitter_rpn_final = hlpst.remove_inp_from_splitter_rpn(
                deepcopy(self.splitter_rpn),
                self.right_combiner_all + self.left_combiner_all,
            )
            return _splitter_rpn_final
        else:
            return self.splitter_rpn

def prepare_states_combined_ind(self, elements_to_remove_comb):
        """Prepare the final list of dictionaries with indices after combiner."""
        partial_rpn_compact = hlpst.remove_inp_from_splitter_rpn(
            deepcopy(self.splitter_rpn_compact), elements_to_remove_comb
        )
        # combiner can have parts from the left splitter, so have to have rpn with states
        partial_rpn = hlpst.splitter2rpn(
            hlpst.rpn2splitter(partial_rpn_compact), other_states=self.other_states
        )
        combined_rpn = hlpst.remove_inp_from_splitter_rpn(
            deepcopy(partial_rpn), self.right_combiner_all + self.left_combiner_all
        )
        if combined_rpn:
            val_r, key_r = hlpst.splits(
                combined_rpn,
                self.inputs,
                inner_inputs=self.inner_inputs,
                cont_dim=self.cont_dim,
            )
            values = list(val_r)
        else:
            values = []
            key_r = []

        keys_out = key_r
        if values:

def prepare_states_combined_ind(self, elements_to_remove_comb):
        """Prepare the final list of dictionaries with indices after combiner."""
        partial_rpn_compact = hlpst.remove_inp_from_splitter_rpn(
            deepcopy(self.splitter_rpn_compact), elements_to_remove_comb
        )
        # combiner can have parts from the left splitter, so have to have rpn with states
        partial_rpn = hlpst.splitter2rpn(
            hlpst.rpn2splitter(partial_rpn_compact), other_states=self.other_states
        )
        combined_rpn = hlpst.remove_inp_from_splitter_rpn(
            deepcopy(partial_rpn), self.right_combiner_all + self.left_combiner_all
        )
        if combined_rpn:
            val_r, key_r = hlpst.splits(
                combined_rpn,
                self.inputs,
                inner_inputs=self.inner_inputs,
                cont_dim=self.cont_dim,
            )