[tools] testbot/orm: Let the Collection Items field pop into existence when needed.

[Francois Gouget]

Collections don't check that it exists so all setting it in the
constructor does is waste memory. Documenting its existence there is
enough.

Signed-off-by: Francois Gouget 
---
 testbot/lib/ObjectModel/Collection.pm | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/testbot/lib/ObjectModel/Collection.pm b/testbot/lib/ObjectModel/Collection.pm
index 4e7a032a3..63d470bbc 100644
--- a/testbot/lib/ObjectModel/Collection.pm
+++ b/testbot/lib/ObjectModel/Collection.pm
@@ -93,7 +93,8 @@ sub new($$$$$;$$@)
               MasterKey           => ComputeMasterKey($MasterColValues),
               # Filter => undef by default
               AllScopeItems       => $AllScopeItems || {},
-              Items               => undef};
+              # Items => undef by default
+  };
   if ($AllScopeItems)
   {
     # Avoid memory cycles in case Items have Detailref properties:
@@ -138,7 +139,8 @@ sub Clone($)
               MasterKey           => $self->{MasterKey},
               # Filter => undef by default
               AllScopeItems       => $self->{AllScopeItems},
-              Items               => undef};
+              # Items => undef by default
+  };
   # See Collection::new()
   weaken($Copy->{AllScopeItems});