stylelint-bundle-worker.js
function mixin(compiler) {
  define(compiler, '_comment', compiler.comment);
  compiler.map = new utils.SourceMap.SourceMapGenerator();
  compiler.position = { line: 1, column: 1 };
  compiler.content = {};
  compiler.files = {};

  for (var key in exports) {
    define(compiler, key, exports[key]);
  }
}
function mixin(compiler) {
  define(compiler, '_comment', compiler.comment);
  compiler.map = new utils.SourceMap.SourceMapGenerator();
  compiler.position = { line: 1, column: 1 };
  compiler.content = {};
  compiler.files = {};

  for (var key in exports) {
    define(compiler, key, exports[key]);
  }
}
Mixin source map support into `compiler`.

@param {Object} `compiler`
@api public