@Override
            public int compare(DockerHostProvider o1, DockerHostProvider o2) {
                return o2.getPriority() - o1.getPriority();
            }
Get the priority of the env provider. A priority of -1 means, this is a 'fallback' called
as last resort.

@return priority, the higher, the earlier the provider is called.
The highest priority of internal providers are not larger than 100.
src/main/java/io/fabric8/maven/docker/access/DockerConnectionDetector.java