Function headersGetter

test/angular/1.7/angular.js:12083–12099

* Returns a function that provides access to parsed headers. * * Headers are lazy parsed when first requested. * @see parseHeaders * * @param {(string|Object)} headers Headers to provide access to. * @returns {function(string=)} Returns a getter function which if called with: * * - if call

(headers)

 *   - if called with no arguments returns an object containing all headers.
 */
function headersGetter(headers) {
  var headersObj;

  return function(name) {
    if (!headersObj) headersObj =  parseHeaders(headers);

    if (name) {
      var value = headersObj[lowercase(name)];
      if (value === undefined) {
        value = null;
      }
      return value;
    }

    return headersObj;
  };
}


/**