'Given a block structure, a block usage key, a transformer, and a list
of keyword arguments representing transformer block fields, verify that
the block structure has the specified values for each transformer block
field.'

def assert_collected_transformer_block_fields(self, block_structure, usage_key, transformer_class, **expectations):

    self.assertGreater(len(expectations), 0)
    self.longMessage = True
    for field in expectations:
        self.assertEqual(expectations[field], block_structure.get_transformer_block_field(usage_key, transformer_class, field), msg=u'in    {}    and    field    {}'.format(transformer_class, repr(field)))
