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 // When there are multiple debuggers, their hooks are called in order.

 var g = newGlobal();

 var log;

 var arr = [];

 function addDebug(msg) {

     var dbg = new Debugger(g);

     dbg.onDebuggerStatement = function (stack) { log += msg; };

     arr.push(dbg);

 }

 addDebug('a');

 addDebug('b');

 addDebug('c');

 log = '';

 assertEq(g.eval("debugger; 0;"), 0);

 assertEq(log, 'abc');

 // Calling debugger hooks stops as soon as any hook returns a resumption value

 // other than undefined.

 arr[0].onDebuggerStatement = function (stack) {

     log += 'a';

     return {return: 1};

 };

 log = '';

 assertEq(g.eval("debugger; 0;"), 1);

 assertEq(log, 'a');