Package assert provides a set of comprehensive testing tools for use with the normal Go testing system. The following is a complete example using assert in a standard test function: if you assert many times, use the format below: Assertions allow you to easily write test code, and are global funcs in the `assert` package. All assertion functions take, as the first argument, the `*testing.T` object provided by the testing framework. This allows the assertion funcs to write the failings and other details to the correct place. Every assertion function also takes an optional string message as the final argument, allowing custom error messages to be appended to the message the assertion method outputs.