function benchmark( b ) {
		var y;
		var i;

		b.tic();
		for ( i = 0; i < b.iterations; i++ ) {
			y = abs( x );
			if ( typeof y !== 'object' ) {
				b.fail( 'should return an object' );
			}
		}
		b.toc();
		if ( isnan( y.get( 0, 0 ) ) || isnan( y.get( shape[0]-1, shape[1]-1 ) ) ) {
			b.fail( 'should not return NaN' );
		}
		b.pass( 'benchmark finished' );
		b.end();
	}
Benchmark function.

@private
@param {Benchmark} b - benchmark instance