@Override public Long parse(String str) {
      if (str == null) {
        return null;
      }
      try {
        return Long.parseLong(str);
      } catch (NumberFormatException xformat) {
        return null;
      }
    }
Reads a value according to this type.
@param in a data input
@return an instance of a value for the type or null
standalone-metastore/metastore-common/src/main/java/org/apache/hadoop/hive/metastore/properties/PropertyType.java