contains illegal final/immutable field "id"

In Kotlin, the "id" field is considered illegal or immutable because it violates the conventions and best practices followed in the language. The steps to explain why this is the case are as follows:

1. Immutability: In Kotlin, it is recommended to use immutable properties whenever possible. Immutable properties are those that cannot be modified after they are initialized. This helps in writing more predictable and maintainable code.

2. Naming Conventions: Kotlin follows specific naming conventions for properties. According to the conventions, properties should be named using camelCase, starting with a lowercase letter. This helps in better readability and consistency of the codebase.

3. "id" Conflict: The name "id" conflicts with a reserved property name in Kotlin. Kotlin provides a built-in property called "id" for defining an identifier or unique identifier for an object. Therefore, using "id" as a property name can lead to confusion and potential conflicts in the code.

4. Backing Field: In Kotlin, properties can have an automatically generated backing field, which is a field that stores the actual value of the property. However, properties with the name "id" have a special meaning and are treated differently. The "id" property is automatically generated based on the object's memory address and should not be modified.

To summarize, using "id" as an immutable field violates the immutability principles, naming conventions, and can lead to conflicts with reserved property names in Kotlin. It is recommended to use a different name for the field to ensure code clarity and adherence to Kotlin's best practices.