static {
        // Those two public constants are initialized here, as they need all the private constants
        // above to be initialized first, but the code style imposes the public constants to be
        // defined above the private ones...
        OS_FAMILY = getOsFamily();
        IS_WINDOWS = isFamily(FAMILY_WINDOWS);
    }

    private Os() {}

    /**

            logger.warn("");
            if (validationReportLevel == ValidationReportLevel.VERBOSE) {
                logger.warn(
                        "Fix reported issues by adjusting plugin configuration or by upgrading above listed plugins. If no upgrade available, please notify plugin maintainers about reported issues.");
            }
            logger.warn(

            if (pathSeparator > 0) {
                value = basedir + expression.substring(pathSeparator);
            }
        }

        /*
         * MNG-4312: We neither have reserved all of the above magic expressions nor is their set fixed/well-known (it
         * gets occasionally extended by newer Maven versions). This imposes the risk for existing plugins to

                    pluginDescriptor = extractPluginDescriptor(artifacts.get(0), plugin);
                } catch (PluginDescriptorParsingException | InvalidPluginDescriptorException e) {
                    // ignore, see above
                }
            }

            discoverPluginComponents(extensionRealm, plugin, pluginDescriptor);

            ExtensionDescriptor extensionDescriptor = null;

                                // MNG-2123: if the previous node was not a range, then it wouldn't have any available
                                // versions. We just clobbered the selected version above. (why? I have no idea.)
                                // So since we are here and this is ranges we must go figure out the version (for a
                                // third time...)

                            "Error evaluating plugin parameter expression: " + expression, e);
                }
            }
        }

        /*
         * MNG-4312: We neither have reserved all of the above magic expressions nor is their set fixed/well-known (it
         * gets occasionally extended by newer Maven versions). This imposes the risk for existing plugins to

        assertFalse(map.containsKey("maven-test:t09-c"), "maven-test:t09-c is in the project");
    }

    /**
     * Setup exactly the same as the above test, except that the child project
     * now depends upon d, which has a transitive dependency on c.  Even though
     * we did list an exclusion on c, it was only from within the context of

        return null;
    }

    public Object getKey() {
        return "artifact " + artifact.getGroupId() + ":" + artifact.getArtifactId();
    }

    public boolean isSnapshot() {
        // Don't consider the artifact's version in here, as this is stored in the directory above that
        return false;
    }

    public int getNature() {

            throw new TransferFailedException("Authorization failed: " + e.getMessage(), e);
        } finally {
            // Remove remaining TransferListener instances (checksum handlers removed in above finally clause)
            if (downloadMonitor != null) {
                wagon.removeTransferListener(downloadMonitor);
            }

            disconnectWagon(wagon);

                configProps.put("aether.transport.wagon.config." + server.getId(), config);

                // Translate to proper resolver configuration properties as well (as Plexus XML above is Wagon specific
                // only) but support only configuration/httpConfiguration/all, see
                // https://maven.apache.org/guides/mini/guide-http-settings.html