writableIf: Indicates an expression that specifies the writability of the attribute.
Defaults to true.
Note: An attribute is only writable if this attribute and the writable attribute are true.
requiredIf: Allows for an expression to be implemented which indicates the conditions in which an attribute is mandatory.
Defaults to false
See
https://github.com/project-chip/zap/blob/master/zcl-builtin/dotdot/README.md#attributes Extra metadata: