@Override
        @Deprecated
        public void setSkin(@Nonnull String skinPlayer) {
            try {
                this.npc.data().set(NPC.PLAYER_SKIN_UUID_METADATA, skinPlayer);
                this.npc.data().set(NPC.PLAYER_SKIN_USE_LATEST, true);

                if (this.npc instanceof SkinnableEntity) {
                    ((SkinnableEntity) this.npc).getSkinTracker().notifySkinChange(true);
                }
                if (this.npc.getEntity() instanceof SkinnableEntity) {
                    ((SkinnableEntity) this.npc.getEntity()).getSkinTracker().notifySkinChange(true);
                }
            } catch (Throwable e) {
                e.printStackTrace();
            }
        }
Implementation of {@link NpcFactory} using Citizens.
helper/src/main/java/me/lucko/helper/npc/CitizensNpcFactory.java