public Expression getNonDefaultValue() {
    checkState(
        !isSetToDefault(),
        "Cannot get non-default value of property %s since its value is set to DEFAULT",
        name);
    return value;
  }
Returns the non-default value of the property. This method should be called only if the
property is not set to DEFAULT.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/relational/sql/ast/Property.java