code: @PublicEvolving
  	public void setResources(ResourceSpec minResources, ResourceSpec preferredResources) {
  		this.minResources = minResources;
  		this.preferredResources = preferredResources;
  	}
docs: Sets the minimum and preferred resources for this contract instance. The resource denotes
  how many memories and cpu cores of the user function will be consumed during the execution.
  
  @param minResources The minimum resource of this operator.
  @param preferredResources The preferred resource of this operator.