lib/Ext/mixin/Sortable.js
function(sorters) {
        // We begin by making sure we are dealing with an array of sorters
        if (!Ext.isArray(sorters)) {
            sorters = [sorters];
        }

        var ln = sorters.length,
            currentSorters = this.getSorters(),
            i, sorter;

        for (i = 0; i < ln; i++) {
            sorter = sorters[i];

            if (typeof sorter === 'string') {
                currentSorters.removeAtKey(sorter);
            }
            else if (typeof sorter === 'function') {
                currentSorters.each(function(item) {
                    if (item.getSorterFn() === sorter) {
                        currentSorters.remove(item);
                    }
                });
            }
            else if (sorter.isSorter) {
                currentSorters.remove(sorter);
            }
        }

        if (!currentSorters.length) {
            this.sorted = false;
        }
    }
function(sorters) {
        // We begin by making sure we are dealing with an array of sorters
        if (!Ext.isArray(sorters)) {
            sorters = [sorters];
        }

        var ln = sorters.length,
            currentSorters = this.getSorters(),
            i, sorter;

        for (i = 0; i < ln; i++) {
            sorter = sorters[i];

            if (typeof sorter === 'string') {
                currentSorters.removeAtKey(sorter);
            }
            else if (typeof sorter === 'function') {
                currentSorters.each(function(item) {
                    if (item.getSorterFn() === sorter) {
                        currentSorters.remove(item);
                    }
                });
            }
            else if (sorter.isSorter) {
                currentSorters.remove(sorter);
            }
        }

        if (!currentSorters.length) {
            this.sorted = false;
        }
    }
This method removes all the sorters in a passed array.
@param {Array} sorters Each value in the array can be a string (property name),
function (sorterFn) or {@link Ext.util.Sorter Sorter} instance.