1  'use strict'
 2  
 3  var experimentalWarnings = new Set();
 4  
 5  function emitExperimentalWarning(feature) {
 6    if (experimentalWarnings.has(feature)) return;
 7    var msg = feature + ' is an experimental feature. This feature could ' +
 8         'change at any time';
 9    experimentalWarnings.add(feature);
10    process.emitWarning(msg, 'ExperimentalWarning');
11  }
12  
13  function noop() {}
14  
15  module.exports.emitExperimentalWarning = process.emitWarning
16    ? emitExperimentalWarning
17    : noop;