Sets the specified value into the field
@param {Mixed} value
@return {Ext.ux.TreePicker} this
function(value) {
        var me = this,
            record;

        me.value = value;

        if (me.store.loading) {
            // Called while the Store is loading. Ensure it is processed by the onLoad method.
            return me;
        }
            
        // try to find a record in the store that matches the value
        record = value ? me.store.getNodeById(value) : me.store.getRootNode();
        if (value === undefined) {
            record = me.store.getRootNode();
            me.value = record.getId();
        } else {
            record = me.store.getNodeById(value);
        }

        // set the raw value to the record's display field if a record was found
        me.setRawValue(record ? record.get(me.displayField) : '');

        return me;
    }