+/**\r
+ Add a group address to the array of group addresses.\r
+ The caller should make sure that no duplicated address\r
+ existed in the array. Although the function doesn't\r
+ assume the byte order of the both Source and Addr, the\r
+ network byte order is used by the caller.\r
+\r
+ @param[in] Source The array of group addresses to add to.\r
+ @param[in] Count The number of group addresses in the Source.\r
+ @param[in] Addr The IP4 multicast address to add.\r
+\r
+ @return NULL if failed to allocate memory for the new groups,\r
+ otherwise the new combined group addresses.\r
+\r
+**/\r