Package utesting provides a standalone replacement for package testing.
This package exists because package testing cannot easily be embedded into a
standalone go program. It provides an API that mirrors the standard library
testing API.
FailNow marks the test as having failed and stops its execution by calling
runtime.Goexit (which then runs all deferred calls in the current goroutine).
Logf formats its arguments according to the format, analogous to Printf, and records
the text in the error log. A final newline is added if not provided.