How to use the lark.exceptions.UnexpectedToken function in lark

if match(item.expect, token):
                    new_item = item.advance()
                    label = (new_item.s, new_item.start, i)
                    new_item.node = node_cache[label] if label in node_cache else node_cache.setdefault(label, SymbolNode(*label))
                    new_item.node.add_family(new_item.s, item.rule, new_item.start, item.node, token)

                    if new_item.expect in self.TERMINALS:
                        # add (B ::= Aai+1.B, h, y) to Q'
                        next_to_scan.add(new_item)
                    else:
                        # add (B ::= Aa+1.B, h, y) to Ei+1
                        next_set.add(new_item)

            if not next_set and not next_to_scan:
                expect = {i.expect.name for i in to_scan}
                raise UnexpectedToken(token, expect, considered_rules = set(to_scan))

            return next_to_scan

def get_action(token):
            state = state_stack[-1]
            try:
                return states[state][token.type]
            except KeyError:
                expected = [s for s in states[state].keys() if s.isupper()]
                raise UnexpectedToken(token, expected, state=state)

def __init__(self, token, expected, considered_rules=None, state=None):
        self.token = token
        self.expected = expected     # XXX str shouldn't necessary
        self.line = getattr(token, 'line', '?')
        self.column = getattr(token, 'column', '?')
        self.considered_rules = considered_rules
        self.state = state
        self.pos_in_stream = getattr(token, 'pos_in_stream', None)

        message = ("Unexpected token %r at line %s, column %s.\n"
                   "Expected one of: \n\t* %s\n"
                   % (token, self.line, self.column, '\n\t* '.join(self.expected)))

        super(UnexpectedToken, self).__init__(message)

for x in l.lex(stream, self.root_lexer.newline_types, self.root_lexer.ignore_types):
                yield x
                parser_state = get_parser_state()
                l.lexer = self.lexers[parser_state]
                l.state = parser_state # For debug only, no need to worry about multithreading
        except UnexpectedCharacters as e:
            # In the contextual lexer, UnexpectedCharacters can mean that the terminal is defined,
            # but not in the current context.
            # This tests the input against the global context, to provide a nicer error.
            root_match = self.root_lexer.match(stream, e.pos_in_stream)
            if not root_match:
                raise

            value, type_ = root_match
            t = Token(type_, value, e.pos_in_stream, e.line, e.column)
            raise UnexpectedToken(t, e.allowed, state=e.state)

]

    logging.basicConfig(level=logging.DEBUG)
    parser = Lark(PROPERTY_GRAMMAR, parser="lalr", start="property", debug=True)

    type_checker = HplTypeChecker(TEST_TOPICS, TEST_FIELDS, TEST_CONSTANTS)
    transformer = PropertyTransformer(type_checker=type_checker)

    for test_str in FAILING_TESTS:
        try:
            tree = parser.parse(test_str)
            tree = transformer.transform(tree)
            print ""
            print test_str
            assert False, "expected failure"
        except UnexpectedToken as e:
            pass
        except UnexpectedCharacters as e:
            pass
        except TypeError as e:
            pass
        except SyntaxError as e:
            pass

    for test_str in PASSING_TESTS:
        print ""
        print test_str
        tree = parser.parse(test_str)
        tree = transformer.transform(tree)
        print tree

    print "All", str(len(FAILING_TESTS) + len(PASSING_TESTS)), "tests passed."