Diffusion akantu (bugfixes/41-group-not-properly-updated-when-cohesive-elements-are-inserted) Change
rAKA/extra_packages/extra-materials/src/material_viscoelastic/material_stiffness_proportional.cc
rAKA/extra_packages/extra-materials/src/material_viscoelastic/material_stiffness_proportional.cc