package com.getbeamapp.transit;

public abstract class AbstractTransitContext extends TransitProxy {

    public AbstractTransitContext() {
        super(null);
        this.rootContext = this;
    }

    @Override
    public abstract TransitProxy eval(String stringToEvaluate, TransitProxy context, Object... arguments);

    private long _nextNativeId = 0;

    public String nextNativeId() {
        return String.valueOf(_nextNativeId++);
    }

}

package com.getbeamapp.transit;

public abstract class AbstractTransitContext extends TransitProxy {

    public AbstractTransitContext() {
        super(null);
        this.rootContext = this;
    }

    @Override
    public abstract TransitProxy eval(String stringToEvaluate, TransitProxy context, Object... arguments);

    private int _nextNativeId = 0;

    public String nextNativeId() {
        return String.valueOf(_nextNativeId++);
    }

}

--- 
+++ 
@@ -10,7 +10,7 @@
     @Override
     public abstract TransitProxy eval(String stringToEvaluate, TransitProxy context, Object... arguments);
 
-    private int _nextNativeId = 0;
+    private long _nextNativeId = 0;
 
     public String nextNativeId() {
         return String.valueOf(_nextNativeId++);
Use `long` for NativeID incrementer
