code: public CreateClusterRequest withStep(StepConfig step) {
          if (this.steps == null) {
              this.steps = new ArrayList<StepConfig>();
          }
          this.steps.add(step);
          return this;
      }
docs: Configure optional step for the cluster. The step will be scheduled and executed after the cluster is ACTIVE.
  And the step also can be added to the cluster by sending AddStepsRequest.
  
  @param step a StepConfig instance to be added.
  @return CreateClusterRequest