Added an asPlayer method to LocalCommandSender, which casts the object to LocalPlayer if possible and throws an exception otherwise.

src/main/java/com/sk89q/worldedit/LocalCommandSender.java

@@ -114,4 +114,8 @@ public abstract class LocalCommandSender {
     public int hashCode() {
         return getName().hashCode();
     }
+
+    public LocalPlayer asPlayer() throws PlayerNeededException {
+        throw new PlayerNeededException();
+    }
 }

src/main/java/com/sk89q/worldedit/LocalPlayer.java

@@ -549,4 +549,8 @@ public abstract class LocalPlayer extends LocalCommandSender {
     public void dispatchCUIHandshake() {
     }
 
+    @Override
+    public LocalPlayer asPlayer() {
+        return this;
+    }
 }

src/main/java/com/sk89q/worldedit/PlayerNeededException.java

@@ -0,0 +1,5 @@
+package com.sk89q.worldedit;
+
+public class PlayerNeededException extends WorldEditException {
+    private static final long serialVersionUID = 1L;
+}