  In this short review, we discuss the approach of the commutator algebra of
covariant derivative to analyse the gravitational theories, starting from the
standard Einstein's general theory of relativity and focusing on the Rastall
theory. After that, we discuss the important role of the torsion in this
mathematical framework. In the Appendix of the paper we analyse the importance
of the nascent gravitational wave astronomy as a tool to discriminate among the
general theory of relativity and alternative theories of gravity.
