AssertEqual checks if the expected and actual are equal.

AsserterrorAs checks if the error is another error.

AssertErrorIs checks if the error is another error.

AssertNoError checks if the error is nil.

AssertTrue checks if the condition is true.

Callers prints the stack trace of everything up til the line where Callers() was invoked.

Diff compares two items and returns a human-readable diff string.