MappedBy reference an unknown target entity property

@Entity
@Table(name = "Category")
public class Category implements Serializable {
 
    @Id
    @GeneratedValue(generator = "increment")
    @GenericGenerator(name = "increment", strategy = "increment")
    @Column(name = "category_id")
    private int category_id;
 
    @Column(name = "name")
    private String name;
 
    @ManyToOne(fetch = FetchType.EAGER)
    @JoinColumn(name = "parent_id", nullable = false)
    private Category parentCategory;
 
    @OneToMany(mappedBy = "category")
    private Set<Category> categories = new HashSet<>(0);
 
    @OneToMany(mappedBy = "category")
    private Set<Product> products = new HashSet<>(0);
 
    //getters and setters......
}

 org.hibernate.AnnotationException: mappedBy reference an unknown target entity property: gigabyte.hibernate.Category.category in gigabyte.hibernate.Category.categories
    at org.hibernate.cfg.annotations.CollectionBinder.bindStarToManySecondPass(CollectionBinder.java:768)
    at org.hibernate.cfg.annotations.CollectionBinder$1.secondPass(CollectionBinder.java:728)
    at org.hibernate.cfg.CollectionSecondPass.doSecondPass(CollectionSecondPass.java:70)
    at org.hibernate.cfg.Configuration.originalSecondPassCompile(Configuration.java:1695)
    at org.hibernate.cfg.Configuration.secondPassCompile(Configuration.java:1424)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1844)

@OneToMany(mappedBy = "category")
    private Set<Category> categories = new HashSet<>(0);

@OneToMany(mappedBy = "parentCategory")
    private Set<Category> categories = new HashSet<>(0);