code: public java.util.List<String> getNatGatewayIds() {
          if (natGatewayIds == null) {
              natGatewayIds = new com.amazonaws.internal.SdkInternalList<String>();
          }
          return natGatewayIds;
      }
docs: <p>
  One or more NAT gateway IDs.
  </p>
  
  @return One or more NAT gateway IDs.