public void terminateWorkflow(String workflowId, String reason) {
        Preconditions.checkArgument(
                StringUtils.isNotBlank(workflowId), "workflow id cannot be blank");
        stub.terminateWorkflow(
                WorkflowServicePb.TerminateWorkflowRequest.newBuilder()
                        .setWorkflowId(workflowId)
                        .setReason(reason)
                        .build());
    }
Terminates the execution of the given workflow instance

@param workflowId the id of the workflow to be terminated
@param reason the reason to be logged and displayed
grpc-client/src/main/java/com/netflix/conductor/client/grpc/WorkflowClient.java