private void log(final Severity severity, final String message, final Exception e) {
        errorReceiverProxy.log(severity, locationFactory.create(locator), getElementId(), message, e);
    }
Build the index name, substituting values from the source document where specified.
For instance, consider an index name of `stroom-index-{_year}`. A field `<string key='_year'>2023</string>` in
the doc root will result in a destination index of `stroom-index-2023` for that document. In this case, because
the field `_year` starts with an underscore, it is not rendered to the doc and instead is solely used in the
index name.
stroom-search/stroom-search-elastic/src/main/java/stroom/search/elastic/indexing/ElasticIndexingFilter.java