How to use the ailment.Expr.Expression function in ailment

def filter_variables(self, atom):
        keys_to_remove = set()

        for k, v in self._variables.items():
            if isinstance(v, Expr.Expression) and (v == atom or v.has_atom(atom)):
                keys_to_remove.add(k)

        for k in keys_to_remove:
            self._variables.pop(k)

def filter_variables(self, atom):
        keys_to_remove = set()

        for k, v in self._variables.items():
            if isinstance(v, ailment.Expr.Expression) and (v == atom or v.has_atom(atom)):
                keys_to_remove.add(k)

        for k in keys_to_remove:
            self._variables.pop(k)

def _convert_claripy_bool_ast(self, cond):
        """
        Convert recovered reaching conditions from claripy ASTs to ailment Expressions

        :return: None
        """

        if isinstance(cond, ailment.Expr.Expression):
            return cond

        if cond.op == "BoolS" and claripy.is_true(cond):
            return cond
        if cond in self._condition_mapping:
            return self._condition_mapping[cond]

        _mapping = {
            'Not': lambda cond_: ailment.Expr.UnaryOp(None, 'Not', self._convert_claripy_bool_ast(cond_.args[0])),
            'And': lambda cond_: ailment.Expr.BinaryOp(None, 'LogicalAnd', (
                self._convert_claripy_bool_ast(cond_.args[0]),
                self._convert_claripy_bool_ast(cond_.args[1]),
            )),
            'Or': lambda cond_: ailment.Expr.BinaryOp(None, 'LogicalOr', (
                self._convert_claripy_bool_ast(cond_.args[0]),
                self._convert_claripy_bool_ast(cond_.args[1]),