golang-github-nebulouslabs-errors-dev - 0.0~git20170430.98e1f05-1.1 main

The errors package is an extension of and drop in replacement for the
standard library errors package. Multiple errors can be composed into a
single error with the Compose function, or a single error can be
extended by adding context using the Extend function. The result can be
checked for the presence of a specific error using Contains. If any of
the underlying composed or extended errors or extensions match,
Contains will return true.
.
This package is especially beneficial during testing, where you may wish
to check for presence of a specific error, but that specific error may
be extending another error or may have been extended by another function
somewhere else in the call stack.