Why chrome.history.onVisited event is fired multiple times on a single visit?

I'm trying to do something when a web browser has loaded a new web page.

my code in background.js is here.

chrome.history.onVisited.addListener(function(details) {
  console.log('onVisited is fired: '+details.url);
});

Unfortunately, console outputs 'onVisited is fired: xxxxx' multiple times per a single event.

help me. plz.