Measuring Performance of a block of code

1. For Synchronous methods :

- (void)testPerformanceReverseString {
    NSString *originalString = @"hi_my_name_is_siddharth";
    [self measureBlock:^{
        [self.someObject reverseString:originalString];
    }];
}

2. For Asynchronous methods :

- (void)testPerformanceOfAsynchronousBlock {
   [self measureMetrics:@[XCTPerformanceMetric_WallClockTime] automaticallyStartMeasuring:YES forBlock:^{
    
    XCTestExpectation *expectation = [self expectationWithDescription:@"performanceTestWithResponse"];
    
    [self.someObject doSomethingThatTakesSomeTimesWithCompletionBlock:^(NSString *result) {
        [expectation fulfill];
    }];
    [self waitForExpectationsWithTimeout:5.0 handler:^(NSError *error) {
    }];
}];
}

These performance measure block gets executed for 10 times consecutively & then the average is calculated, & on the basis of this average performance result gets created & baseline is accepted for further evaluation.
The performance result is compared with the previous test results & baseline with a customizable max standard deviation.

Found a mistake? Have a question or improvement idea? Let me know.