private String getApiIndex(String orgId, String apiId, String version) {
        return "API::" + orgId + "|" + apiId + "|" + version; //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
    }
Generates an in-memory key for an api, used to index the client for later quick
retrieval.

@return an api key index
gateway/engine/core/src/main/java/io/apiman/gateway/engine/impl/InMemoryRegistry.java