
 
        Returns the path where dropped data should be placed in the
 tree.
 
 Interpretation of this value depends on the drop mode set on the
 component. If the drop mode is DropMode.USE_SELECTION
 or DropMode.ON, the return value is the path in the
 tree over which the data has been (or will be) dropped.
 null indicates that the drop is over empty space,
 not associated with a particular path.
 
 If the drop mode is DropMode.INSERT, the return value
 refers to the path that should become the parent of the new data,
 in which case getChildIndex() indicates where the
 new item should be inserted into this parent path. A
 null path indicates that no parent path has been
 determined, which can happen for multiple reasons:
 
    - The tree has no model
    
 - There is no root in the tree
    
 - The root is collapsed
    
 - The root is a leaf node
 
 
 It is up to the developer to decide if and how they wish to handle
 the 
null case. 
 
 If the drop mode is DropMode.ON_OR_INSERT,
 getChildIndex can be used to determine whether the
 drop is on top of the path itself (-1) or the index
 at which it should be inserted into the path (values other than
 -1).
        
        
Returns:
    the drop path 
See Also:
  JTree.DropLocation.getChildIndex(),