Entity classes have some issues while using retrofit - kotlin

Question

I am getting this error while getting a response from an API.
Sometimes, it works fine but 8/10 times it crashes and shows me this error
java.lang.NullPointerException: Attempt to invoke virtual method 'int java.lang.String.hashCode()' on a null object reference
at com.example.newsapi.db.Entities.Source.hashCode(Unknown Source:2)
at com.example.newsapi.db.Entities.Article.hashCode(Unknown Source:50)
This is the Article entity
#Entity(tableName = "Article_Table")
data class Article(
#PrimaryKey(autoGenerate = true)
val id: Int?=null,
val author: String,
val content: String,
val description: String,
val publishedAt: String,
val source: Source,
val title: String,
val url: String,
val urlToImage: String
): Serializable
This is the Source class declared in the Article class
data class Source(
val id: String,
val name: String
)
Here is where I'm trying to put that Article object inside a Bundle
setOnClickListener {
val bundle = Bundle().apply {
putSerializable("article", currentArticle)
}
when (from) {
"BreakingNewsFragment" -> findNavController().navigate(R.id.action_breakingNewsFragment_to_articleFragment, bundle)
"SearchNewsFragment" -> findNavController().navigate(R.id.action_searchNewsFragment_to_articleFragment, bundle)
"SavedNewsFragment" -> findNavController().navigate(R.id.action_savedNewsFragment_to_articleFragment, bundle)
}
}
Here is the API call function
#GET("v2/top-headlines")
suspend fun getBreakingNews(
#Query("country")
countryCode: String = "us",
#Query("page")
pageNumber : Int = 1,
#Query("apiKey")
apiKey: String = API_KEY
): Response<NewsResponse>
calling that function from the repository
suspend fun getBreakingNews(countryCode: String, pageNumber: Int): Response<NewsResponse> {
return RetrofitInstance.api.getBreakingNews(
countryCode = countryCode,
pageNumber = pageNumber
)
}
calling that repository function from the viewmodel
fun getBreakingNews(countryCode: String){
viewModelScope.launch(Dispatchers.IO) {
breakingNews.postValue(Resource.Loading())
val response = articleRepository.getBreakingNews(countryCode, breakingNewsPage)
breakingNews.postValue(handleBreakingNewsResponse(response))
}
}
Here is the NewsResponse Class
data class NewsResponse(
val articles: List<Article>,
val status: String,
val totalResults: Int
)