Instructs the OpenEdge BP Server to assign an available task to a given performer (a user).
When a task is created, it can be available or assigned. You may need to assign an available task or reassign an assigned task. In order for any work (including completion) to occur on a task, the task must be assigned to a user. If a task is available but not assigned, the Assign( ) method will assign the task to a specified user.