public V put(K key, V value) {
        int ordinal = key.ordinal();
        V existingValue = values[ordinal];
        values[ordinal] = value;
        if (existingValue == null) {
            size++;
        }
        return existingValue;
    }
@author James Chen
@see java.util.EnumMap
turms-server-common/src/main/java/im/turms/server/common/infra/collection/FastEnumMap.java