jquery plugin: call to method within plugin

(function( $ ){

    var methods = {
        init : function( options ) {
            var settings = $.extend( {
                'location' : 'top',
                'background-color' : 'blue'
            }, options);

            alert ( settings.location );
        },
        show : function( ) {
            // IS
        },
        hide : function( ) {
            // GOOD
        },
        update : function( content ) {
            // !!!
        },
        display : function ( test1, test2 ) {
            var test1 = test1;
            alert ( "test1: " + test1 + "\ntest2: " + test2 );
            self.display2( test2 );
        },
        display2 : function ( test3 ) {
            alert ( "test3: " + test3 );
        }
    };

    $.fn.tooltip = function( method ) {

        // Method calling logic
        if ( methods[method] ) {
            return methods[ method ].apply( this, Array.prototype.slice.call( arguments, 1 ));
        } else if ( typeof method === 'object' || ! method ) {
            return methods.init.apply( this, arguments );
        } else {
            $.error( 'Method ' +  method + ' does not exist on jQuery.tooltip' );
        }

    };

})( jQuery );

$(document).ready(function() {

// calls the init method
    $('div').tooltip();

// calls the init method
    $('div').tooltip({
        'location' : 'left'
    });

    $().tooltip('display', 'John', '316');
});