public String getVersion() {
    return version;
  }
The version of the DTD or Schema. Prior to 8.1 this value was of the format "8_0". With 8.1 and
later the value is of the format "8.1". Values should match constants in {@link CacheXml} like
{@link CacheXml#VERSION_8_1}.

@return the version

@since GemFire 8.1
geode-core/src/main/java/org/apache/geode/internal/cache/xmlcache/CacheXmlVersion.java