private static int compareStrings(String s1, String s2) {
        if (s1 == null && s2 == null) {
            return 0;
        }

        if (s1 == null /* && s2 != null */) {
            return -1;
        }

        if (
        /* s1 != null && */ s2 == null) {
            return 1;
        }

        return s1.compareTo(s2);
    }

        public int compare(Option opt1, Option opt2) {
            String s1 = opt1.getOpt() != null ? opt1.getOpt() : opt1.getLongOpt();
            String s2 = opt2.getOpt() != null ? opt2.getOpt() : opt2.getLongOpt();
            return s1.compareToIgnoreCase(s2);
        }
    }

    private static class CLIManagerExtension extends CLIManager {
        public Collection<Option> getOptions() {

                                + (s1.isEmpty() ? "" : ", missing " + s1)
                                + (s2.isEmpty() ? "" : ", unexpected " + s2));
            }
            return given;
        }
        return computed;
    }

    private static void addPhase(
            Graph graph, Graph.Vertex before, Graph.Vertex after, org.apache.maven.api.Lifecycle.Phase phase) {

        }

        ArtifactRepository other = (ArtifactRepository) obj;

        return eq(getId(), other.getId());
    }

    protected static <T> boolean eq(T s1, T s2) {
        return Objects.equals(s1, s2);
    }

    public Authentication getAuthentication() {
        return authentication;
    }

    public void setAuthentication(Authentication authentication) {

        }

        return location != null ? new org.apache.maven.model.InputLocation(location) : null;
    }

    private static boolean equals(String s1, String s2) {
        String c1 = s1 == null ? "" : s1.trim();
        String c2 = s2 == null ? "" : s2.trim();
        return c1.equals(c2);
    }

    private static Severity getSeverity(ModelBuildingRequest request, int errorThreshold) {