\[~nicolas.peru] we already have a separate rule about private fields: RSPEC-1068, and because the advice is different. If they're private and not used, they're dead code. If they're not private and _apparently_ unused, they might still be accessed directly by classes that just aren't currently 'visible'.
* Moreover for me there is no intersection between this rule and rule RSPEC-1068. In case of RSPEC-1068 we're looking for unused fields whereas here we're looking for fields that ARE really used but never updated and so which should be declared as 'final'
* I would decrease the remediation cost to 2 min and associate this rule to the Maintainability > Understandability characteristic
* This rule would be limited at first to private fields but I would not mention this limitation
\[~ann.campbell.2] I want to expand the scope of this rule for Swift "Fields *and variables* that are never updated should be constant". WDYT can I do it in subtask for this rule?