workflow from console app for multiple records ?

a console app will use ExecuteWorkflowRequest and run on demand workflow.

ExecuteWorkflowRequest works with a single record. Please tell me how to run it without
passing EntityId.

I want to process multiple records with it so have not one EntityId.

How to avoid passing EntityId ?

ExecuteWorkflowRequest request = new ExecuteWorkflowRequest()
{
    WorkflowId = _workflowId,
    EntityId = _leadId
};

Guide me please.

Thanks