website/static/playground.js/getCLIOptions
function getCLIOptions() {
  return OPTIONS.sort()
    .map(function(option) {
      var elem = document.getElementById(option);
      var match = elem.parentNode.textContent.match(/--\S+/);
      if (!match) {
        return null;
      }
      var name = match[0];
      if (elem.tagName === "SELECT") {
        if (elem.value === elem.options[0].value) {
          return null;
        }
        return [name, elem.value];
      } else if (elem.type === "number") {
        if (elem.value === elem.getAttribute("value")) {
          return null;
        }
        return [name, elem.value];
      } else if (elem.type === "checkbox") {
        if (!elem.checked) {
          return null;
        }
        return [name, true];
      }
      return null;
    })
    .filter(Boolean);
}