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<body>
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var iframe = document.createElement('iframe');
document.body.appendChild(iframe);
iframe.contentWindow.document.open();
iframe.contentWindow.document.write('<body></body>');
iframe.contentWindow.document.close();
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var event_count = Number(sessionStorage.event_count);
sessionStorage.event_count = event_count + 1;
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sessionStorage.event_count = 0;
setTimeout(function() {
console.log(sessionStorage.event_count);
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