public Collection<SimpleTableSegment> extractNotExistTableFromRoutineBody(final RoutineBodySegment routineBody) {
        Collection<SimpleTableSegment> result = new LinkedList<>();
        for (ValidStatementSegment each : routineBody.getValidStatements()) {
            Optional<CreateTableStatement> createTable = each.getCreateTable();
            if (createTable.isPresent() && !createTable.get().isIfNotExists()) {
                result.add(createTable.get().getTable());
            }
        }
        return result;
    }
@Test
    void assertNotExistTableFromRoutineBody() {
        RoutineBodySegment routineBodySegment = new RoutineBodySegment(0, 3);
        ValidStatementSegment validStatement = new ValidStatementSegment(0, 1);
        validStatement.setSqlStatement(mock(SQLStatement.class));
        routineBodySegment.getValidStatements().add(validStatement);
        ValidStatementSegment newValidStatement = new ValidStatementSegment(0, 1);
        validStatement.setSqlStatement(mock(CreateTableStatement.class));
        routineBodySegment.getValidStatements().add(newValidStatement);
        Collection<SimpleTableSegment> nonExistingTables = tableExtractor.extractNotExistTableFromRoutineBody(routineBodySegment);
        assertThat(nonExistingTables.size(), is(1));
    }