code: function createFromMap(mapObject, content, url) {
    url = url || '<source>';
    if ('string' == typeof mapObject) {
      try {
        mapObject = JSON.parse(mapObject);
      } catch (err) {
        mapObject = {
          version: 3,
          names: [],
          mappings: '',
          file: ''
        };
      }
    }
    if (emptySources(mapObject)) {
      mapObject.sources = [url];
      mapObject.sourcesContent = [content];
    }
  
    return SourceMapGenerator.fromSourceMap(new SourceMapConsumer(mapObject));
  }
docs: Create source map from 'mapObject' and 'content'
  @param {Object} mapObject
  @param {String} content
  @param {String} [url]
  @returns {SourceMapGenerator}