code: public DescribeSubnetGroupsResult withSubnetGroups(SubnetGroup... subnetGroups) {
          if (this.subnetGroups == null) {
              setSubnetGroups(new java.util.ArrayList<SubnetGroup>(subnetGroups.length));
          }
          for (SubnetGroup ele : subnetGroups) {
              this.subnetGroups.add(ele);
          }
          return this;
      }
docs: <p>
  An array of subnet groups. Each element in the array represents a single subnet group.
  </p>
  <p>
  <b>NOTE:</b> This method appends the values to the existing list (if any). Use
  {@link #setSubnetGroups(java.util.Collection)} or {@link #withSubnetGroups(java.util.Collection)} if you want to
  override the existing values.
  </p>
  
  @param subnetGroups
  An array of subnet groups. Each element in the array represents a single subnet group.
  @return Returns a reference to this object so that method calls can be chained together.