presto-hive/src/main/java/io/prestosql/plugin/hive/HiveSessionProperties.java/InsertExistingPartitionsBehavior/valueOf
class InsertExistingPartitionsBehavior:        public static InsertExistingPartitionsBehavior valueOf(String value, boolean immutablePartition)
        {
            InsertExistingPartitionsBehavior enumValue = valueOf(value.toUpperCase(ENGLISH));
            if (immutablePartition) {
                checkArgument(enumValue != APPEND, "Presto is configured to treat Hive partitions as immutable. %s is not allowed to be set to %s", INSERT_EXISTING_PARTITIONS_BEHAVIOR, APPEND);
            }

            return enumValue;
        }