How to pass String parameter through REST API while starting process instance in BPMS 6 ?

Issue

• We are using below REST API to start process instance in BPMS 6

http://localhost:8080/business-central/rest/runtime/com.sample:Project1:1.0.0/process/Project1.TestProcess/start?map_Id=1234

In the above example Id is a String and get the following exception on the client side if 1234 is being pass in as input.

WorkflowRuntimeException thrown with message '[com.sample.Project1.TestProcess:7 - Command:2] -- java.lang.ClassCastException: java.lang.Long cannot be cast to java.lang.String'
org.kie.remote.services.rest.exception.KieRemoteRestOperationException: [com.sample.Project1.TestProcess:7 - Command:2] -- java.lang.ClassCastException: java.lang.Long cannot be cast to java.lang.String  at org.kie.remote.services.rest.exception.KieRemoteRestOperationException.internalServerError(KieRemoteRestOperationException.java:151) at org.kie.remote.services.cdi.ProcessRequestBean.doKieSessionOperation(ProcessRequestBean.java:305)