anticipate the inevitable network failures that accompany being physically
  disconnected from the network, and adjust it's behavior accordingly.

  It is more than simply understanding that m2 cannot go and check for the
  latest version of some snapshot artifact. If m2 is offline, SCM operations
  cannot succeed; no artifact downloads can take place, regardless of whether

                    unknown = true;
                }
                if (selected == null) {
                    selected = type;
                } else if (unknown) {
                    // More than one filtered value, and we don't know how to handle at least one of them.
                    // TODO: add a plugin mechanism for allowing plugin to specify their selection algorithm.
                    return Optional.empty();

        requireNonNull(pluginBindings);
        final int len = pluginBindings.length;
        if (len < 2 || len % 2 != 0) {
            throw new IllegalArgumentException("Plugin bindings must have more than 0, even count of elements");
        }

        HashMap<String, LifecyclePhase> lifecyclePhaseBindings = new HashMap<>(len / 2);
        for (int i = 0; i < len; i = i + 2) {

    /**
     * Module information for the path specified at construction time.
     * This map is usually either empty if no module was found, or a singleton map.
     * It may however contain more than one entry if module hierarchy was detected,
     * in which case there is one key per sub-directory.
     *
     * <p>This map may contain null values if the constructor was invoked with {@code resolve}

 * There should be no big surprises here, although you may notice that the methods accept
 * <code>java.lang.CharSequence</code> rather than <code>java.lang.String</code>. This is provided mainly as a
 * convenience, to enable developers to pass things like <code>java.lang.StringBuffer</code> directly into the logger,
 * rather than formatting first by calling <code>toString()</code>.
 *
 * @since 4.0.0
 */
@Experimental
@Provider

     * The returned list of versions is only dependent on the configured repositories and their contents.
     * The supplied request may also refer to a single concrete version rather than a version range.
     * In this case though, the result contains simply the (parsed) input version, regardless of the
     * repositories and their contents.
     *
     * @param session the session to use

                     */
                    type = cache.selectPathType(pathTypes, filter, path).orElse(type);
                }
                addPathElement(type, info.getKey());
                // There is usually no more than one element, but nevertheless allow multi-modules.
            }
            /*
             * If the dependency has no module information, search for an artifact of the same groupId

                    problems,
                    Severity.FATAL,
                    Version.V20,
                    "modelVersion",
                    null,
                    "of '" + string + "' is newer than the versions supported by this version of Maven: "
                            + validVersions + ". Building this project requires a newer version of Maven.",
                    tracker);

    /**
     * Merges values from the specified parent model into the given child model. Implementations are expected to keep
     * parent and child completely decoupled by injecting deep copies of objects into the child rather than the original
     * objects from the parent.
     *
     * @param child The child model into which to merge the values inherited from the parent, must not be
     *            <code>null</code>.

                     */
                    type = cache.selectPathType(pathTypes, filter, path).orElse(type);
                }
                addPathElement(type, info.getKey());
                // There is usually no more than one element, but nevertheless allow multi-modules.
            }
            /*
             * If the dependency has no module information, search for an artifact of the same groupId