@SuppressWarnings("unchecked")
    @Override
    public final IReadWriteStream<ApiRequest> getRequestDataHandler(ApiRequest request,
            IPolicyContext context, Object policyConfiguration) {
        return requestDataHandler(request, context, (C) policyConfiguration);
    }
@see io.apiman.gateway.engine.policy.IDataPolicy#getRequestDataHandler(io.apiman.gateway.engine.beans.ApiRequest, io.apiman.gateway.engine.policy.IPolicyContext, java.lang.Object)
gateway/engine/policies/src/main/java/io/apiman/gateway/engine/policies/AbstractMappedDataPolicy.java