ProductBuilder.java

@AutoValue
abstract class ProductBuilder {
    @SerializedName("id")
    abstract long getId();

    @SerializedName("name")
    abstract String getName();

    @SerializedName("price")
    abstract float getPrice();

    static TypeAdapter<ProductBuilder> typeAdapter(Gson gson) {
        return new AutoValue_ProductBuilder.GsonTypeAdapter(gson);
    }

    static Builder builder() {
        return new AutoValue_ProductBuilder.Builder();
    }

    @AutoValue.Builder
    static abstract class Builder {
        abstract Builder setId(long id);
        abstract Builder setName(String name);
        abstract Builder setPrice(float price);
        abstract ProductBuilder build();
    }
}