index.js
function normalizeOptions(obj) {
  for (var key in obj) {
    if (utils.optsKeys.indexOf(key) > -1) {
      obj.options = obj.options || {};
      obj.options[key] = obj[key];
      delete obj[key];
    }
  }
  return obj;
}
function normalizeOptions(obj) {
  for (var key in obj) {
    if (utils.optsKeys.indexOf(key) > -1) {
      obj.options = obj.options || {};
      obj.options[key] = obj[key];
      delete obj[key];
    }
  }
  return obj;
}
function normalizeOptions ( obj ) { for ( var key in obj ) { if ( utils . optsKeys . indexOf ( key ) > - 1 ) { obj . options = obj . options || { } ; obj . options [ key ] = obj [ key ] ; delete obj [ key ] ; } } return obj ; }
Move reserved options properties from `obj` to `obj.options`
Move reserved options properties from obj to obj . options