As wraps pkg/errors.As.

Cause wraps pkg/errors.Cause.

Errorf wraps errors.Errorf.

Is is a fork of the Is() method from `pkg/errors` which takes as its target an error Code instead of an error.

IsCoded reports whether the error is a codedError at all, and thus, whether it makes sense to check it against Is at all.

MarshalJSON returns the provided error as a json object (as a string) representing a codedError.

New yields an error which is a coded error, using the special value ErrUncoded as the type.

NewCoded yields an error of an unexported type that incorporates the code, allowing us to distinguish between "errors with the same code" and "the exact text of the message".

UnmarshalJSON converts the byte slice into a codedError.

Unwrap is a convenience function that just calls pkg/errors/Unwrap.

Wrap is a convenience function that just calls pkg/errors/Wrap.

Wrapf is a convenience function that just calls pkg/errors/Wrapf.

ErrUncoded denotes an error that doesn't have a more specific code.

Code is an error code which can be used to check against a given error.