Adds this document to the document tree.
HRESULT Attach( IDebugDocumentHelper* pddhParent );
[in] The document tree where this document will be added. May be NULL.
The method returns an HRESULT. Possible values include, but are not limited to, those in the following table.
The method succeeded.
This method adds this document to the document tree, using pddhParent as the parent. If the pddhParent is NULL, this document will be the top-level document.