MuonStationTypeBuilder . Move state to external cache to be passed by the caller
MuonStationTypeBuilder . Move state to external cache to be passed by reference from the called. No state allows all methods to become const , which then allows methods of the called to become const.
Do not know if this exact form will work, but this is more or less the standard transformations we have applied to other places to make things MT safe.
Do not know if this is important to be done in MT safe way , but this is one way to go about it.
Did not check for other clients and not sure if this quick try will even work.
CI can tell us perhaps. E.g one might want to keep this cache alive in some way if it was supposed to participate
in lifetime for a full job rather then calculation in the alg to be used for a validity range ...