Collection<String> c1=Arrays.asList("red","cyan");
Collection<String> c2=Arrays.asList("red","blue");
Collection<String> c3=Arrays.asList("pink","tan");
System.out.println(Collections.disjoint(c1, c2));
System.out.println(Collections.disjoint(c1, c3));
Collections.disjoint();是什么意思,在jdk帮助文档找不到