code: public DescribeGatewayInformationResult withGatewayNetworkInterfaces(NetworkInterface... gatewayNetworkInterfaces) {
          if (this.gatewayNetworkInterfaces == null) {
              setGatewayNetworkInterfaces(new com.amazonaws.internal.SdkInternalList<NetworkInterface>(gatewayNetworkInterfaces.length));
          }
          for (NetworkInterface ele : gatewayNetworkInterfaces) {
              this.gatewayNetworkInterfaces.add(ele);
          }
          return this;
      }
docs: <p>
  A <a>NetworkInterface</a> array that contains descriptions of the gateway network interfaces.
  </p>
  <p>
  <b>NOTE:</b> This method appends the values to the existing list (if any). Use
  {@link #setGatewayNetworkInterfaces(java.util.Collection)} or
  {@link #withGatewayNetworkInterfaces(java.util.Collection)} if you want to override the existing values.
  </p>
  
  @param gatewayNetworkInterfaces
  A <a>NetworkInterface</a> array that contains descriptions of the gateway network interfaces.
  @return Returns a reference to this object so that method calls can be chained together.