src/java.base/share/classes/sun/nio/ch/MembershipRegistry.java

*** 82,98 ****
       */
      void add(MembershipKeyImpl key) {
          InetAddress group = key.group();
          List<MembershipKeyImpl> keys;
          if (groups == null) {
!             groups = new HashMap<InetAddress,List<MembershipKeyImpl>>();
              keys = null;
          } else {
              keys = groups.get(group);
          }
          if (keys == null) {
!             keys = new LinkedList<MembershipKeyImpl>();
              groups.put(group, keys);
          }
          keys.add(key);
      }
  
--- 82,98 ----
       */
      void add(MembershipKeyImpl key) {
          InetAddress group = key.group();
          List<MembershipKeyImpl> keys;
          if (groups == null) {
!             groups = new HashMap<>();
              keys = null;
          } else {
              keys = groups.get(group);
          }
          if (keys == null) {
!             keys = new LinkedList<>();
              groups.put(group, keys);
          }
          keys.add(key);
      }