protected PropertySchema schemaOf(String[] keys) {
    return PropertySchema.NONE;
  }
Determines the schema from the property key fragments.
@param keys the key fragments
@return the schema, {@link PropertySchema#NONE} if no such schema is known
standalone-metastore/metastore-common/src/main/java/org/apache/hadoop/hive/metastore/properties/PropertyManager.java