public java.util.List<String> getTagKeys() {
        if (tagKeys == null) {
            tagKeys = new com.amazonaws.internal.SdkInternalList<String>();
        }
        return tagKeys;
    }
<p>
A tag key or keys for which you want to return all matching clusters that are associated with the specified key
or keys. For example, suppose that you have clusters that are tagged with keys called <code>owner</code> and
<code>environment</code>. If you specify both of these tag keys in the request, Amazon Redshift returns a
response with the clusters that have either or both of these tag keys associated with them.
</p>

@return A tag key or keys for which you want to return all matching clusters that are associated with the
        specified key or keys. For example, suppose that you have clusters that are tagged with keys called
        <code>owner</code> and <code>environment</code>. If you specify both of these tag keys in the request,
        Amazon Redshift returns a response with the clusters that have either or both of these tag keys
        associated with them.
aws-java-sdk-redshift/src/main/java/com/amazonaws/services/redshift/model/DescribeClustersRequest.java