private RegionMetadata loadFromStream(final InputStream stream) {
        try {
            return LegacyRegionXmlLoadUtils.load(stream);
        } catch (IOException exception) {
            throw new SdkClientException(
                    "Error parsing region metadata from input stream",
                    exception);
        }
    }
Loads region metadata from file location specified in
{@link #REGIONS_FILE_OVERRIDE} property.
Returns null if no such property exists.

@throws SdkClientException if any error occurs while loading the
                              metadata file.
aws-java-sdk-core/src/main/java/com/amazonaws/regions/LegacyRegionXmlMetadataBuilder.java