def test_access(self, root):
layout = Plasma()
layout.root = root
layout.add('a')
now = datetime.now()
assert layout.root.find_payload('a').last_accessed < now
layout.focus('a')
assert layout.root.find_payload('a').last_accessed > now
def test_focus(self, root):
layout = Plasma()
layout.root = root
a, b, c, d = 'abcd'
layout.add(a)
layout.add(b)
layout.add(c)
layout.add(d)
assert layout.focus_first() == 'a'
assert layout.focus_last() == 'd'
assert layout.focus_next('b') == 'c'
assert layout.focus_previous('c') == 'b'
layout.focus('c')
assert layout.focused is c