code: function StackMapper(sourcemap) {
    if (!(this instanceof StackMapper)) return new StackMapper(sourcemap);
    if (typeof sourcemap !== 'object') 
      throw new Error('sourcemap needs to be an object, please use convert-source-map module to convert it from any other format\n' +
                      'See: https://github.com/thlorenz/stack-mapper#obtaining-the-source-map');
  
    this._sourcemap = sourcemap;
    this._prepared = false;
  }
docs: Creates a Stackmapper that will use the given source map to map error trace locations
  
  @name StackMapper
  @private
  @constructor
  @param {Object} sourcemap