function toStringBench() {
      var bench = this,
          error = bench.error,
          hz = bench.hz,
          id = bench.id,
          stats = bench.stats,
          size = stats.sample.length,
          pm = '\xb1',
          result = bench.name || (_.isNaN(id) ? id : '<Test #' + id + '>');

      if (error) {
        var errorStr;
        if (!_.isObject(error)) {
          errorStr = String(error);
        } else if (!_.isError(Error)) {
          errorStr = join(error);
        } else {
          // Error#name and Error#message properties are non-enumerable.
          errorStr = join(_.assign({ 'name': error.name, 'message': error.message }, error));
        }
        result += ': ' + errorStr;
      }
      else {
        result += ' x ' + formatNumber(hz.toFixed(hz < 100 ? 2 : 0)) + ' ops/sec ' + pm +
          stats.rme.toFixed(2) + '% (' + size + ' run' + (size == 1 ? '' : 's') + ' sampled)';
      }
      return result;
    }
Displays relevant benchmark information when coerced to a string.

@name toString
@memberOf Benchmark
@returns {string} A string representation of the benchmark instance.