How to use the wilson/application.getApplicationInstances function in wilson

exports.syncdb = function() {
    var application = require('wilson/application'),
        appInstances = application.getApplicationInstances(),
        pieshop = require('pieshop'),
        backend = pieshop.settings.get_addon('backend'),
        sys = require('sys');

    var table_creations = [],
        deferred = [];

    for(var app_name in appInstances) {
        var app = appInstances[app_name];
        for(var model_name in app.models) {
            var model = app.models[model_name];

            var table_fields = [];
            for(var field_name in model.prototype._meta.fields) {
                var backendField = model.prototype._meta.get_field_by_name(field_name).getBackendField(backend),
                    column = backendField.getColumn(field_name),

}

    if(appInstance) {
        var appCommand = appInstance.app.commands[command];
        if(appCommand) {
            appCommand.apply(appInstance, process.argv.slice(3));
        } else {
            sys.puts('Could not find the command '+app_and_command);
            if(app === appInstance.name) {
                sys.puts('Available commands within '+app);
                for(var command_name in appInstance.app.commands) {
                    sys.puts('\t'+[app, command_name].join(':'));
                }
            } else {
                sys.puts('All apps and commands:');
                var appInstances = application.getApplicationInstances();
                for(var app_name in appInstances) {
                    sys.puts('\t'+app_name+':');
                    for(var command in appInstances[app_name]) {
                        sys.puts('\t\t'+command);
                    }
                }
            }        
        }
    }
};