old_contents: var shitList = {};
  
  shitList.shitList = function (hostname) {
    var values = {};
    values[hostname] = true;
  
    return new Promise(function (resolve, reject) {
      chrome.storage.sync.set(values, function (results) {
        resolve();
      });
    });
  }.bind(shitList);
  
  shitList.deShitList = function (hostname) {
  
    return new Promise(function (resolve, reject) {
      chrome.storage.sync.remove(hostname, function (results) {
        resolve();
      });
    });
  }.bind(shitList);
  
  module.exports = shitList;
  
new_contents: var shitList = {};
  
  shitList.shitList = function (hostname) {
    var values = {};
    values[hostname] = true;
  
    return new Promise(function (resolve, reject) {
      chrome.storage.sync.set(values, function (results) {
        resolve();
      });
    });
  }.bind(shitList);
  
  shitList.deShitList = function (hostname) {
  
    return new Promise(function (resolve, reject) {
      chrome.storage.sync.remove(hostname, function (results) {
        resolve();
      });
    });
  }.bind(shitList);
  
  shitList.isShitListed = function (hostname) {
    return new Promise(function (resolve, reject) {
      chrome.storage.sync.get(hostname, function (results) {
        if (results[hostname]) {
          resolve(true);
        } else {
          resolve(false);
        }
      });
    });
  }.bind(shitList);
  
  module.exports = shitList;
  
subject: Add isShitListed function.