如何使用Reduce操作对对象的两个字段执行求和。例如classPojo{publicPojo(inta,intb){super();this.a=a;this.b=b;}inta;intb;publicintgetA(){returna;}publicvoidsetA(inta){this.a=a;}publicintgetB(){returnb;}publicvoidsetB(intb){this.b=b;}}Pojoobject1=newPojo(1,1);Pojoobject2=newPojo(2,2);Pojoobject3=newPojo(3,3);Pojoobject4=