function onPreTest( error ) {
		// If the pretests failed, don't run the benchmark multiple times...
		if ( error ) {
			opts.repeats = 1;
			opts.iterations = 1;
			return clbk( name, opts, benchmark );
		}
		// If a user specified an iteration number, we can begin running benchmarks...
		if ( opts.iterations ) {
			return clbk( name, opts, benchmark );
		}
		// Determine iteration number:
		iterations( name, opts, benchmark, onIterations );
	}
Callback invoked upon completing pretests.

@private
@param {Error} [error] - error object
@returns {void}