android – Erro com tipo personalizado retornando null

Tenho que pegar uma imagem da minha API atraves de um objeto personalizado(PokemonItem) mas esta dando um erro que me retorna somente null no meu PokemonImage. Alguem pode me ajudar? Ja tentei usar conversores mas nao deu certo

Log:

private final com.example.pokedex.model.PokemonImage images = null;
                                                     ^
FAILURE: Build failed with an exception.

* What went wrong:
    Execution failed for task ':app:kaptDebugKotlin'.
    > A failure occurred while executing org.jetbrains.kotlin.gradle.internal.KaptExecution
       > java.lang.reflect.InvocationTargetException (no error message)

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more 
log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

Deprecated Gradle features were used in this build, making it incompatible with Gradle 7.0.
Use '--warning-mode all' to show the individual deprecation warnings.
See https://docs.gradle.org/6.5/userguide/command_line_interface.html#sec:command_line_warnings

BUILD FAILED in 2s

PokemonItem.java (para onde sou direcionado ao clicar no erro)

private final com.example.pokedex.model.PokemonImage images = null;
@org.jetbrains.annotations.NotNull()

classe PokemonItem

import androidx.room.Entity
import androidx.room.PrimaryKey
import androidx.room.TypeConverters
import com.example.pokedex.Converters
import com.google.gson.annotations.SerializedName
import java.io.Serializable

@Entity(tableName = "PokemonItem")
@TypeConverters(Converters::class)
data class PokemonItem(
    @PrimaryKey(autoGenerate = false)
    var id: String = "",
    @SerializedName("name") val nome: String = "",
    val images: PokemonImage,
    val types: List<String>,
    val abilities: List<PokemonAbility>,
    val hp: String = ""

) : Serializable

data class PokemonImage

data class PokemonImage(
@SerializedName("small") val smallImageUrl: String
)