public java.util.List<TypeVersionSummary> getTypeVersionSummaries() {
        if (typeVersionSummaries == null) {
            typeVersionSummaries = new com.amazonaws.internal.SdkInternalList<TypeVersionSummary>();
        }
        return typeVersionSummaries;
    }
<p>
A list of <code>TypeVersionSummary</code> structures that contain information about the specified extension's
versions.
</p>

@return A list of <code>TypeVersionSummary</code> structures that contain information about the specified
        extension's versions.
aws-java-sdk-cloudformation/src/main/java/com/amazonaws/services/cloudformation/model/ListTypeVersionsResult.java