public java.util.List<String> getCacheNodeIdsToRemove() {
        if (cacheNodeIdsToRemove == null) {
            cacheNodeIdsToRemove = new com.amazonaws.internal.SdkInternalList<String>();
        }
        return cacheNodeIdsToRemove;
    }
<p>
A list of cache node IDs to be removed. A node ID is a numeric identifier (0001, 0002, etc.). This parameter is
only valid when <code>NumCacheNodes</code> is less than the existing number of cache nodes. The number of cache
node IDs supplied in this parameter must match the difference between the existing number of cache nodes in the
cluster or pending cache nodes, whichever is greater, and the value of <code>NumCacheNodes</code> in the request.
</p>
<p>
For example: If you have 3 active cache nodes, 7 pending cache nodes, and the number of cache nodes in this
<code>ModifyCacheCluster</code> call is 5, you must list 2 (7 - 5) cache node IDs to remove.
</p>

@return A list of cache node IDs to be removed. A node ID is a numeric identifier (0001, 0002, etc.). This
        parameter is only valid when <code>NumCacheNodes</code> is less than the existing number of cache nodes.
        The number of cache node IDs supplied in this parameter must match the difference between the existing
        number of cache nodes in the cluster or pending cache nodes, whichever is greater, and the value of
        <code>NumCacheNodes</code> in the request.</p>
        <p>
        For example: If you have 3 active cache nodes, 7 pending cache nodes, and the number of cache nodes in
        this <code>ModifyCacheCluster</code> call is 5, you must list 2 (7 - 5) cache node IDs to remove.
aws-java-sdk-elasticache/src/main/java/com/amazonaws/services/elasticache/model/ModifyCacheClusterRequest.java