code: public DescribeResourceGroupsRequest withResourceGroupArns(String... resourceGroupArns) {
          if (this.resourceGroupArns == null) {
              setResourceGroupArns(new java.util.ArrayList<String>(resourceGroupArns.length));
          }
          for (String ele : resourceGroupArns) {
              this.resourceGroupArns.add(ele);
          }
          return this;
      }
docs: <p>
  The ARN that specifies the resource group that you want to describe.
  </p>
  <p>
  <b>NOTE:</b> This method appends the values to the existing list (if any). Use
  {@link #setResourceGroupArns(java.util.Collection)} or {@link #withResourceGroupArns(java.util.Collection)} if
  you want to override the existing values.
  </p>
  
  @param resourceGroupArns
  The ARN that specifies the resource group that you want to describe.
  @return Returns a reference to this object so that method calls can be chained together.