@Entity(name = "EntityB")
	public static class EntityB {
		...

		@OneToMany(fetch = FetchType.EAGER)
		Collection<EntityC> attributes = new LinkedList<>();

		@OneToMany(fetch = FetchType.EAGER)
		Set<EntityD> entityDS = new HashSet<>();

	}

	@Entity(name = "EntityC")
	public static class EntityC {
		...
	}

	@Entity(name = "EntityD")
	public static class EntityD {
		...
	}

@Test
	public void testIt(SessionFactoryScope scope) {

		scope.inTransaction(
				session -> {
					EntityC c = new EntityC( 1l, "c" );
					EntityC c1 = new EntityC( 2l, "c1" );

					EntityD d = new EntityD( 1l, "d" );
					EntityD d1 = new EntityD( 2l, "d1" );
					EntityD d2 = new EntityD( 3l, "d2" );

					EntityB b = new EntityB( 1l, "b" );

					b.addAttribute( c );
					b.addAttribute( c1 );

					b.addEntityD( d );
					b.addEntityD( d1 );
					b.addEntityD( d2 );

					session.save( c );
					session.save( c1 );

					session.save( d );
					session.save( d1 );
					session.save( d2 );

					session.save( b );
				}
		);
		
		
		scope.inTransaction(
				session -> {
					EntityB entityB = session.find( EntityB.class, 1l );

					assertThat( entityB.getAttributes().size() ).isEqualTo( 2 );
				}
		);
	}