code: public DescribeDBSubnetGroupsResult withDBSubnetGroups(DBSubnetGroup... dBSubnetGroups) {
          if (this.dBSubnetGroups == null) {
              setDBSubnetGroups(new com.amazonaws.internal.SdkInternalList<DBSubnetGroup>(dBSubnetGroups.length));
          }
          for (DBSubnetGroup ele : dBSubnetGroups) {
              this.dBSubnetGroups.add(ele);
          }
          return this;
      }
docs: <p>
  A list of <a>DBSubnetGroup</a> instances.
  </p>
  <p>
  <b>NOTE:</b> This method appends the values to the existing list (if any). Use
  {@link #setDBSubnetGroups(java.util.Collection)} or {@link #withDBSubnetGroups(java.util.Collection)} if you want
  to override the existing values.
  </p>
  
  @param dBSubnetGroups
  A list of <a>DBSubnetGroup</a> instances.
  @return Returns a reference to this object so that method calls can be chained together.