Warning: This function is
EXPERIMENTAL. The behaviour of this function, the
name of this function, and anything else documented about this
function may change without notice in a future release of PHP.
Use this function at your own risk.
Return the SDO_Sequence for this SDO_DataObject.
Accessing the SDO_DataObject through the SDO_Sequence interface
acts on the same SDO_DataObject instance data,
but preserves ordering across properties.
Return Values
The SDO_Sequence for this SDO_DataObject, or returns NULL if the
SDO_DataObject is not of a type which can have a sequence.