'Internal relationships (TargetMode == \'Internal\' in the XML) should
have a relative ref, e.g. \'../slideLayouts/slideLayout1.xml\', for
the target_ref attribute.'

def it_should_have_relative_ref_for_internal_rel(self):

    part = Mock(name=u'part', partname=PackURI(u'/ppt/media/image1.png'))
    baseURI = u'/ppt/slides'
    rel = _Relationship(None, None, part, baseURI)
    assert (rel.target_ref == u'../media/image1.png')
