Any checks if err matches any matchers.

Is check if err matches all matchers.

NewKind returns a Kind with the given msg.

NewStackTrace returns a new StackTrace, skipping the given number of frames, to avoid including the caller.

Error represents an error of some Kind, implements the error interface.

Kind represents the kind of an error, from a Kind you can generate as many Error instances as you want of this Kind.

StackTrace is stack of Frames from innermost (newest) to outermost (oldest).

Matcher matches a given error.