def test_compare():
a = Link('a', 'a', 'a')
b = Link('a', 'a', 'b')
assert a != b
assert a <= b
b.annotation = 'a'
assert a == b
def test_repr():
l = Link('foo', 'bar')
assert repr(l) == "Link(%s, %s)" % (repr('foo'), repr('bar'))
l.annotation = 'x'
assert repr(l) == "Link(%s, %s, %s)" % (repr('foo'), repr('bar'),
repr('x'))
l.target = None
assert repr(l) == "Link(%s, annotation=%s)" % (repr('foo'), repr('x'))