Server.getTPS(); results in a NoSuchMethodError

[Timtendo12]

double[] tps = this.plugin.getServer().getTPS();

Any other methods on getServer() afaik work fine but getTPS() results in a error

org.bukkit.command.CommandException: Unhandled exception executing command 'tps' in plugin MineCraftBetaTest v1.0.0
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:41)
	at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:162)
	at org.bukkit.craftbukkit.CraftServer.dispatchCommand(CraftServer.java:346)
	at net.minecraft.server.NetServerHandler.handleCommand(NetServerHandler.java:736)
	at net.minecraft.server.NetServerHandler.chat(NetServerHandler.java:701)
	at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:694)
	at net.minecraft.server.Packet3Chat.a(Packet3Chat.java:33)
	at net.minecraft.server.NetworkManager.b(NetworkManager.java:226)
	at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:89)
	at net.minecraft.server.NetworkListenThread.a(SourceFile:105)
	at net.minecraft.server.MinecraftServer.h(MinecraftServer.java:453)
	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:363)
	at net.minecraft.server.ThreadServerApplication.run(SourceFile:422)
Caused by: java.lang.NoSuchMethodError: org.bukkit.Server.getTPS()[D
	at nl.timtendo12.commands.TPSCommand.onCommand(TPSCommand.java:20)
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:39)
	... 12 more
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