IsSameString asserts that two strings are equal. The two strings are normalized (whitespace removed) before doing a ==. Also note that two strings can be the same even if they're of different types.
IsSameType asserts that got is the same type as want.
DeepAllowUnexported creates an option to allow compare of unexported types in the given list of types. see https://github.com/google/go-cmp/issues/40#issuecomment-328615283