presto-main/src/main/java/io/prestosql/operator/scalar/JsonFunctions.java/JsonFunctions/getJsonObjectValue
class JsonFunctions:    public static Object getJsonObjectValue(Type valueType, ConnectorSession session, Block block, int position)
    {
        Object objectValue = valueType.getObjectValue(session, block, position);
        if (objectValue instanceof SqlDecimal) {
            objectValue = ((SqlDecimal) objectValue).toBigDecimal();
        }
        return objectValue;
    }