values. A matcher is able to describe itself to give feedback when it fails. Matcher implementations should NOT directly implement this interface. Instead, extend the BaseMatcher abstract class, which will ensure that the Matcher API can grow to support new features and remain compatible with all Matcher implementations. For easy access to common Matcher implementations, use the static factory methods in CoreMatchers. N.B. Well designed matchers should be immutable. See Also: CoreMatchers, BaseMatcher...