constructor(root, options) {
    super(root, options);
    options = options || {};
    this.column = 1;
    this.lineno = 1;
    this.contents = {};
    this.filename = options.filename;
    this.dest = options.dest;

    var sourcemap = options.sourcemap;
    this.basePath = sourcemap.basePath || '.';
    this.inline = sourcemap.inline;
    this.comment = sourcemap.comment;
    if (this.dest && extname(this.dest) === '.css') {
      this.basename = basename(this.dest);
      this.dest = dirname(this.dest);
    } else {
      this.basename = basename(this.filename, extname(this.filename)) + '.css';
    }
    this.utf8 = false;

    this.map = new SourceMapGenerator({
      file: this.basename,
      sourceRoot: sourcemap.sourceRoot || null
    });
  }
Initialize a new `SourceMapper` generator with the given `root` Node
and the following `options`.

@param {Node} root
@api public