  Model transformations are the cornerstone of Model-Driven Engineering, and
provide the essential mechanisms for manipulating and transforming models.
Checking whether the output of a model transformation is correct is a manual
and error-prone task, this is referred to as the oracle problem in the software
testing literature. The correctness of the model transformation program is
crucial for the proper generation of its output, so it should be tested.
Metamorphic testing is a testing technique to alleviate the oracle problem
consisting on exploiting the relations between different inputs and outputs of
the program under test, so-called metamorphic relations. In this paper we give
an insight into our approach to generically define metamorphic relations for
model transformations, which can be automatically instantiated given any
specific model transformation.
