changes the method get_assembly to get_one_assemblies in test code.
changes the method get_assembly to get_one_assemblies in test code.

megamsys/megam_api,arunkumarsekar06/megam_api,indykish/megam_api,LogeshEswar/megam_api,thomasalrin/megam_api,rajthilakmca/megam_api,vinomca-megam/megam_api,rathishvbr/megam_api