code: function PackageMemberListReadStream(dirToScan) {
      sjl.throwTypeErrorIfEmpty('PackageMemberListReadStream', 'dirToScan', dirToScan, String);
      this._pathToRead = dirToScan;
      Readable.call(this, {
          encoding: 'utf8',
          objectMode: false,
          highWaterMark: 100000,
      });
  }
docs: Our package member list to markdown-fragments readable stream.  It
  reads our srcs directory and outputs a markdown-fragments friendly list
  of all the packages and members in said directory.
  @param dirToScan {String} - Dir to scan for list.
  @param options {Object|undefined} - Optional.  Readable stream options.
  @constructor {PackageMemberListReadStream}