Returns, by reference in bounds, the size and x origin to place value at.

  Returns, by reference in bounds, the size and x origin to
place value at. The calling method is responsible for determining
the Y location. If bounds is null, a newly created
Rectangle should be returned,
otherwise the value should be placed in bounds and returned.
Returns: a Rectangle containing the node dimensions, or null if node has no dimension
Parameters:
- value - the value to be represented
- row - row being queried
- depth - the depth of the row
- expanded - true if row is expanded, false otherwise
- bounds - a Rectangle containing the size needed to represent value