code: function removeExportAnnotationsFromComment(comment) {
    // Remove @export annotations.
    comment = comment.replace(EXPORT_REGEX, '')
  
    // Split into lines, remove empty comment lines, then recombine.
    comment = comment.split('\n')
        .filter(function(line) { return !/^ *\*? *$/.test(line); })
        .join('\n');
  
    return comment;
  }
docs: Take the original block comment and prep it for the externs by removing
  export annotations and blank lines.
  
  @param {string}
  @return {string}