code: public static FlowContext createFlowContext(final String uuid) {
          if (null == uuid) {
              throw new IllegalArgumentException("Flow context cannot be null");
          }
          final FlowContext flowContext = new FlowContextImpl(uuid);
          addFlowContext(flowContext);
          return flowContext;
      }
docs: Create FlowContext and put it on ThreadLocal.
  If there is a FlowContext in the ThreadLocal it will be overridden.
  
  @param uuid
  @return The flowContext that is now in the ThreadLocal