setField(cmd, "fid", 0x1234);
        setField(cmd, "typeOfLock", (byte) 0x05);
        setField(cmd, "newOpLockLevel", (byte) 0x01);
        setField(cmd, "timeout", 3000L);
        // arrays of one lock and one unlock range
        LockingAndXRange lock = new LockingAndXRange(false);
        lock.encode(new byte[20], 0); // initialise fields by encoding to set pid etc (though not needed)
        setField(lock, "pid", 123);

    * `dict`의 값(value)는 `float`타입이다. (각 아이템의 가격(price))

#### `Optional`

`str`과 같이 타입을 선언할 때 `Optional`을 쓸 수도 있는데, "선택적(Optional)"이기때문에 `None`도 될 수 있습니다:

```Python hl_lines="1  4"
{!../../docs_src/python_types/tutorial009.py!}
```

`Optional[str]`을 `str` 대신 쓰게 되면, 특정 값이 실제로는 `None`이 될 수도 있는데 항상 `str`이라고 가정하는 상황에서 에디터가 에러를 찾게 도와줄 수 있습니다.

#### Generic(제네릭) 타입

이 타입은 대괄호 안에 매개변수를 가지며, 종류는:

* `List`

    return unmodifiableRowSortedTable(table);
  }

  @Override
  protected Map<String, Integer> makePopulatedMap() {
    RowSortedTable<String, Character, Integer> table = TreeBasedTable.create();
    table.put("one", 'a', 1);
    table.put("two", 'a', 2);
    table.put("three", 'a', 3);
    table.put("four", 'b', 4);
    return unmodifiableRowSortedTable(table).column('a');
  }

    return unmodifiableTable(table);
  }

  @Override
  protected Map<String, Integer> makePopulatedMap() {
    Table<String, Character, Integer> table = HashBasedTable.create();
    table.put("one", 'a', 1);
    table.put("two", 'a', 2);
    table.put("three", 'a', 3);
    table.put("four", 'b', 4);
    return unmodifiableTable(table).column('a');
  }

  }

  @Override
  protected Map<String, Integer> makePopulatedMap() {
    Table<Character, String, Integer> table = HashBasedTable.create();
    table.put('a', "one", 2);
    table.put('a', "two", 4);
    table.put('a', "three", 6);
    table.put('b', "four", 8);
    return transformValues(table, TableCollectionTest.DIVIDE_BY_2).row('a');
  }

#
# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements.  See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership.  The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License.  You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *