public static final PluginCoordinates fromPolicySpec(String pluginPolicySpec) {
        if (pluginPolicySpec == null) {
            return null;
        }
        int startIdx = 7;
        int endIdx = pluginPolicySpec.indexOf('/');
        
        String [] split = pluginPolicySpec.substring(startIdx, endIdx).split(":"); //$NON-NLS-1$
        String groupId = split[0];
        String artifactId = split[1];
        String version = split[2];
        String classifier = null;
        String type = null;
        if (split.length == 4) {
            type = split[3];
        }
        if (split.length == 5) {
            classifier = split[3];
            type = split[4];
        }
        PluginCoordinates rval = new PluginCoordinates(groupId, artifactId, version, classifier, type);
        return rval;
    }
Returns the plugin coordinates associated with the given plugin policy specification.  The format
of a plugin policy specification is:

plugin:groupId:artifactId:version[:classifier][:type]/org.example.plugins.PluginImpl

@param pluginPolicySpec the policy specification
@return plugin coordinates
common/plugin/src/main/java/io/apiman/common/plugin/PluginCoordinates.java