[alexisespinosa]

In version v1812 I was surprised with the warning that the constraint specification 'preservePatches' is too old:

Calculating distribution of cells
Selecting decompositionMethod hierarchical [6]
--> FOAM Warning : 
    Using 'preservePatches' constraint specification.
    This constraint keyword is deemed to be 54 months old.

preservePatches : adding constraints to keep owner of faces in patches 
2
(
front
back
)
 on same processor. This only makes sense for cyclics.

What should we use instead for preserving cyclic faces in the same processor?