silverstripe-framework/tests/DataObjectTest.yml

PageComment:
   comment1:
      Name: Joe
      Comment: This is a test comment
   comment2:
      Name: Jane
      Comment: This is another test comment
   comment3:
      Name: Bob
      Comment: Another comment
   comment4:
      Name: Bob
      Comment: Second comment by Bob
   comment5:
      Name: Ernie
      Comment: This is a test comment
   comment6:
      Name: Jimmy
      Comment: This is another test comment
   comment7:
      Name: Dean
      Comment: Another comment
   comment8:
      Name: Dean
      Comment: Second comment by Dean

Page:
   home:
      Title: Home
      Comments: =>PageComment.comment1,=>PageComment.comment2
   page1:
      Title: First Page
      Content: <p>Some test content</p>
      Comments: =>PageComment.comment3,=>PageComment.comment4 
   page2:
      Title: Second Page

DataObjectTest_Team:
   team1:
      Title: Team 1
   team2:
      Title: Team 2
      
DataObjectTest_Player:
   player1:
      FirstName: Player 1
   player2:
      FirstName: Player 2
      Teams: =>DataObjectTest_Team.team1,=>DataObjectTest_Team.team2