@JsonPropertyDescription(DESCRIPTION_PREFIX + "the number of streams received by a feed.")
    @JsonProperty("metaDataStreamsReceived")
    public List<DocRef> getMetaDataStreamsReceivedDocRefs() {
        return metaDataStreamsReceivedDocRefs;
    }
Create a list of {@link DocRef} objects that are associated with a single {@link InternalStatisticKey}
stroom-statistics/stroom-statistics-impl/src/main/java/stroom/statistics/impl/InternalStatisticsConfig.java