我想从下面的hashmap中获取公共时间集的工作日

import java.time.LocalDate;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

public class Main {
    public static void main(String[] args) {
        // 示例hashmap，键为日期，值为布尔类型的变量，表示是否为工作日
        Map<LocalDate, Boolean> hashmap = new HashMap<>();
        hashmap.put(LocalDate.of(2022, 1, 1), false);
        hashmap.put(LocalDate.of(2022, 1, 2), false);
        hashmap.put(LocalDate.of(2022, 1, 3), true);
        hashmap.put(LocalDate.of(2022, 1, 4), true);
        hashmap.put(LocalDate.of(2022, 1, 5), true);
        hashmap.put(LocalDate.of(2022, 1, 6), true);
        hashmap.put(LocalDate.of(2022, 1, 7), true);

        // 给定的时间范围
        LocalDate startDate = LocalDate.of(2022, 1, 1);
        LocalDate endDate = LocalDate.of(2022, 1, 7);

        Set<LocalDate> commonWorkingDays = getCommonWorkingDays(hashmap, startDate, endDate);
        System.out.println("公共时间集的工作日：");
        for (LocalDate date : commonWorkingDays) {
            System.out.println(date);
        }
    }

    public static Set<LocalDate> getCommonWorkingDays(Map<LocalDate, Boolean> hashmap, LocalDate startDate, LocalDate endDate) {
        Set<LocalDate> commonWorkingDays = new HashSet<>();

        for (LocalDate date : hashmap.keySet()) {
            if (hashmap.get(date)) {
                boolean isCommonWorkingDay = true;
                for (LocalDate otherDate : hashmap.keySet()) {
                    if (hashmap.get(otherDate) && !date.equals(otherDate)) {
                        if (!isDateInRange(otherDate, startDate, endDate) || !hashmap.containsKey(otherDate)) {
                            isCommonWorkingDay = false;
                            break;
                        }
                    }
                }
                if (isCommonWorkingDay && isDateInRange(date, startDate, endDate)) {
                    commonWorkingDays.add(date);
                }
            }
        }

        return commonWorkingDays;
    }

    public static boolean isDateInRange(LocalDate date, LocalDate startDate, LocalDate endDate) {
        return !date.isBefore(startDate) && !date.isAfter(endDate);
    }
}