Using Path constraints

    fun <T: StatusState> verifyPathConstraints(tx: LedgerTransaction, primaryStateClass: Class<T>){

        val commandValue = tx.commands.requireSingleCommand<AgreementContract.Commands>().value    // get the command

        val txPath = getPath(tx, primaryStateClass, commandValue)       // call the getPath() utility function to get the Path of the transaction

        val inputStatus = requireSingleInputStatus(tx, primaryStateClass)       // get the Primary state status

        val allowedPaths: List<PathConstraint<T>> = when (inputStatus){        // populate the when clause mapping: statuses -> allowed constraints
            null -> listOf(
                    PathConstraint(Commands.Propose(), PROPOSED, MultiplicityConstraint(0))
            )
            PROPOSED -> listOf(
                    PathConstraint(Commands.Reject(), REJECTED),
                    PathConstraint(Commands.Agree(), AGREED)
            )
            REJECTED -> listOf(
                    PathConstraint(Commands.Repropose(), PROPOSED)
            )
            AGREED -> listOf(
                    PathConstraint(Commands.Complete(), null, outputMultiplicityConstraint = MultiplicityConstraint(0))
            )
            else -> listOf()
        }

        requireThat {
            "txPath must be allowed by PathConstraints for inputStatus $inputStatus." using verifyPath(txPath, allowedPaths) // call the utility function to check the paths
        }
    }