code: function insertPersonData(filename, tableSchema) {
    return getSampleData(filename).then(
        function(data) {
          var rows = data.map(function(obj) {
            obj.dateOfBirth = convertDate(obj.dateOfBirth);
            obj.dateOfDeath = convertDate(obj.dateOfDeath);
            return tableSchema.createRow(obj);
          });
          return db.insert().into(tableSchema).values(rows);
        });
  }
docs: Inserts data in the database.
  @param {string} filename The name of the file holding JSON data.
  @param {!movie.db.schema.Actor|!movie.db.schema.Director} tableSchema The
  schema of the table corresponding to the data.
  @return {!IThenable<!lf.query.Insert>}