Added show- and hideOnlinePlayers() method

src/main/kotlin/net/axay/kspigot/extensions/bukkit/EntityExtensions.kt

@@ -84,6 +84,20 @@ fun Player.appear() {
     onlinePlayers.filter { it != this }.forEach { it.showPlayer(KSpigotMainInstance, this) }
 }
 
+/**
+ * Hides all online players from this player.
+ */
+fun Player.hideOnlinePlayers() {
+    onlinePlayers.filter { it != this }.forEach { this.hidePlayer(KSpigotMainInstance, it) }
+}
+
+/**
+ * Shows all online players to this player.
+ */
+fun Player.showOnlinePlayers() {
+    onlinePlayers.filter { it != this }.forEach { this.showPlayer(KSpigotMainInstance, it) }
+}
+
 /**
  * Kicks the player from the server.
  */