code: public static JsonEntityField eval(Mirror<?> mirror, String name, Method getter, Method setter) {
          JsonEntityField jef = new JsonEntityField();
          jef.declaringClass = mirror.getType();
          jef.setGenericType(getter.getGenericReturnType());
          jef.name = name;
          jef.ejecting = new EjectByGetter(getter);
          jef.injecting = new InjectBySetter(setter);
          jef.mirror = Mirror.me(getter.getReturnType());
          return jef;
      }
docs: 根据名称获取字段实体, 默认以set优先