@Entity
public class Main {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    @ManyToOne
    private Connector connector;

    @ManyToOne(fetch = FetchType.LAZY)
    private Sub sub;
  
    }

@Entity
public class Connector {

    @Id
    private Long id;

    @ManyToOne
    @Fetch(FetchMode.SELECT)
    private Sub sub;
  }

ava.lang.StackOverflowError
	at org.hibernate.sql.results.graph.entity.EntityInitializer.findFirstEntityInitializer(EntityInitializer.java:34)
	at org.hibernate.sql.results.graph.entity.internal.EntitySelectFetchInitializerBuilder.createInitializer(EntitySelectFetchInitializerBuilder.java:45)
	at org.hibernate.sql.results.graph.entity.internal.EntityFetchSelectImpl.buildEntitySelectFetchInitializer(EntityFetchSelectImpl.java:92)
	at org.hibernate.sql.results.graph.entity.internal.EntityFetchSelectImpl.lambda$createAssembler$0(EntityFetchSelectImpl.java:70)
	at org.hibernate.sql.results.internal.ResultsHelper$1.resolveInitializer(ResultsHelper.java:117)
	at org.hibernate.sql.results.graph.entity.internal.EntityFetchSelectImpl.createAssembler(EntityFetchSelectImpl.java:67)
	at org.hibernate.sql.results.graph.entity.AbstractEntityInitializer.<init>(AbstractEntityInitializer.java:172)
	at org.hibernate.sql.results.graph.entity.internal.EntityJoinedFetchInitializer.<init>(EntityJoinedFetchInitializer.java:48)
	at org.hibernate.sql.results.graph.entity.internal.EntityFetchJoinedImpl.buildEntityJoinedFetchInitializer(EntityFetchJoinedImpl.java:127)
	at org.hibernate.sql.results.graph.entity.internal.EntityFetchJoinedImpl.lambda$getEntityInitializer$0(EntityFetchJoinedImpl.java:100)
	at org.hibernate.sql.results.internal.ResultsHelper$1.resolveInitializer(ResultsHelper.java:117)
	at org.hibernate.sql.results.graph.entity.internal.EntityFetchJoinedImpl.getEntityInitializer(EntityFetchJoinedImpl.java:97)
	at org.hibernate.sql.results.graph.entity.AbstractNonLazyEntityFetch.createAssembler(AbstractNonLazyEntityFetch.java:68)
	at org.hibernate.sql.results.graph.entity.AbstractEntityInitializer.<init>(AbstractEntityInitializer.java:172)
	at org.hibernate.sql.results.graph.entity.internal.EntityResultInitializer.<init>(EntityResultInitializer.java:35)
	at org.hibernate.sql.results.graph.entity.internal.EntityResultImpl.lambda$createResultAssembler$0(EntityResultImpl.java:91)
	at org.hibernate.sql.results.internal.ResultsHelper$1.resolveInitializer(ResultsHelper.java:117)
	at org.hibernate.sql.results.graph.entity.internal.EntityResultImpl.createResultAssembler(EntityResultImpl.java:82)
	at org.hibernate.sql.results.jdbc.internal.StandardJdbcValuesMapping.resolveAssemblers(StandardJdbcValuesMapping.java:53)