Sometimes server data is uncertain, so it is necessary to verify and protect data
 on client.
Other commonly used @JsonKey annotations include:

/// Tell json_serializable to use "defaultValue" if the JSON doesn't

/// contain this key or if the value is `null`.

@JsonKey

defaultValue:

false

final

bool

isAdult

/// When `true` tell json_serializable that JSON must contain the key,

/// If the key doesn't exist, an exception is thrown.

@JsonKey

required

true

final

String

id

/// When `true` tell json_serializable that generated code should

/// ignore this field completely.

@JsonKey

ignore:

true

final