private RegionMetadata loadOverrideMetadataIfExists() {
        RegionMetadata metadata = loadFromSystemProperty();

        if (metadata == null) {
            InputStream override = RegionUtils.class
                    .getResourceAsStream(OVERRIDE_ENDPOINTS_RESOURCE_PATH);
            if (override != null) {
                metadata = loadFromStream(override);
                IOUtils.closeQuietly(override, LOG);
            }
        }

        return metadata;
    }
A region metadata builder that loads the data by looking at all the
legacy metadata locations.
aws-java-sdk-core/src/main/java/com/amazonaws/regions/LegacyRegionXmlMetadataBuilder.java