@Entity(tableName = "test_class")
public class TestClass
{
    @Entity(tableName = "inner_one")
    public static class InnerClassOne
    {
        @PrimaryKey(autoGenerate = true)
        @ColumnInfo(name = "id")
        private long idInnerOne;

        @ColumnInfo(name = "field")
        private double field;

        // getters and setters
    }

    @Entity(tableName = "inner_two")
    public static class InnerClassTwo
    {
        @PrimaryKey(autoGenerate = true)
        @ColumnInfo(name = "id")
        private long idInnerTwo;

        @ColumnInfo(name = "str")
        private String str;

        // getters and setters
    }

    @Entity(tableName = "inner_tree")
    public static class InnerClassTree
    {
        @PrimaryKey(autoGenerate = true)
        @ColumnInfo(name = "id")
        private long idInnerTree;

        @ColumnInfo(name = "id_test_class")
        @ForeignKey(entity = TestClass.class, parentColumns = "id", childColumns = "id_test_class",
        onDelete = ForeignKey.CASCADE, onUpdate = ForeignKey.CASCADE)
        long idTest;

        @ColumnInfo(name = "ser")
        private int ser;

        @ColumnInfo(name = "vid")
        private int vid;

        // getters and setters
    }

    @PrimaryKey(autoGenerate = true)
    private long id;

    @ColumnInfo(name = "id_one")
    @ForeignKey(entity = InnerClassOne.class, parentColumns = "id", childColumns = "id_one",
    onDelete = ForeignKey.CASCADE, onUpdate = ForeignKey.CASCADE)
    private long idOne;

    @ColumnInfo(name = "id_two")
    @ForeignKey(entity = InnerClassTwo.class, parentColumns = "id", childColumns = "id_two",
    onDelete = ForeignKey.CASCADE, onUpdate = ForeignKey.CASCADE)
    private long idTwo;


    private InnerClassOne innerOne;
    private InnerClassTwo innerTwo;
    private List<InnerClassTree> lst;

    // getters and setters

}