public GroupConfiguration withConfiguration(GroupConfigurationItem... configuration) {
        if (this.configuration == null) {
            setConfiguration(new java.util.ArrayList<GroupConfigurationItem>(configuration.length));
        }
        for (GroupConfigurationItem ele : configuration) {
            this.configuration.add(ele);
        }
        return this;
    }
<p>
The configuration currently associated with the group and in effect.
</p>
<p>
<b>NOTE:</b> This method appends the values to the existing list (if any). Use
{@link #setConfiguration(java.util.Collection)} or {@link #withConfiguration(java.util.Collection)} if you want
to override the existing values.
</p>

@param configuration
       The configuration currently associated with the group and in effect.
@return Returns a reference to this object so that method calls can be chained together.
aws-java-sdk-resourcegroups/src/main/java/com/amazonaws/services/resourcegroups/model/GroupConfiguration.java