resource_timing_2 library Null safety

Resource Timing Level 2


The interface enables retrieval and analysis of detailed network timing data regarding the loading of an application's resources. An application can use the timing metrics to determine, for example, the length of time it takes to fetch a specific resource, such as an XMLHttpRequest, <SVG>, image, or script. The interface's properties create a resource loading timeline with high-resolution timestamps for network events such as redirect start and end times, fetch start, DNS lookup start and end times, response start and end times, etc.. Additionally, the interface extends PerformanceEntry with other properties which provide data about the size of the fetched resource as well as the type of resource that initiated the fetch.