Panel Header should not be inline with the layout

Is: If you create a panel with a dock -top header and items with layout hbox, the docked item will be aligned to the left.

What I expect: The docked item should be aligned top and the two items underneath should be left to right

Example:

ntype: 'panel',
headers: [{
    dock: 'top'
}],
layout: {ntype: 'hbox', align: 'stretch'},
items: [{
    html: 'item a'
}, {
    html: 'item b'
}]