function unmapAllExcept(keystrokes, domain) {
        if (_isDomainApplicable(domain)) {
            var modes = [normal, insert];
            modes.forEach(function(mode) {
                var _mappings = new Trie();
                keystrokes = keystrokes || [];
                for (var i = 0, il = keystrokes.length; i < il; i++) {
                    var ks = KeyboardUtils.encodeKeystroke(keystrokes[i]);
                    var node = mode.mappings.find(ks);
                    if (node) {
                        _mappings.add(ks, node.meta);
                    }
                }
                delete mode.mappings;
                mode.mappings = _mappings;
                mode.map_node = _mappings;
            });
        }
    }
Unmap all keybindings except those specified.

@param {array} keystrokes the keybindings you want to keep.
@param {regex} [domain=null] a Javascript regex pattern to identify the domains that this mapping will be removed.

@example

unmapAllExcept(['E','R','T'], /google.com|twitter.com/);