I have the following code below. Setting aligned to both left and right does nothing. Both buttons are left aligned. I also tried setting the alignment to centered. The buttons are still left aligned. Is there any reason why these are ignored?

dockedItems:
[
{
dock: 'top',
title: 'Dashboard',
xtype: 'toolbar',
items:
[
{
xtype: 'button',
ui: 'mask',
iconCls: 'refresh',
stretch: false,
align: 'left',
handler: refresh
},
{
xtype: 'button',
ui: 'mask',
iconCls: 'add',
stretch: false,
align: 'right',
handler: refresh
}
]
}