public CoreNetwork withNetworkFunctionGroups(CoreNetworkNetworkFunctionGroup... networkFunctionGroups) {
        if (this.networkFunctionGroups == null) {
            setNetworkFunctionGroups(new java.util.ArrayList<CoreNetworkNetworkFunctionGroup>(networkFunctionGroups.length));
        }
        for (CoreNetworkNetworkFunctionGroup ele : networkFunctionGroups) {
            this.networkFunctionGroups.add(ele);
        }
        return this;
    }
<p>
The network function groups associated with a core network.
</p>
<p>
<b>NOTE:</b> This method appends the values to the existing list (if any). Use
{@link #setNetworkFunctionGroups(java.util.Collection)} or
{@link #withNetworkFunctionGroups(java.util.Collection)} if you want to override the existing values.
</p>

@param networkFunctionGroups
       The network function groups associated with a core network.
@return Returns a reference to this object so that method calls can be chained together.
aws-java-sdk-networkmanager/src/main/java/com/amazonaws/services/networkmanager/model/CoreNetwork.java