Gets the structure element that serves as parent for the structure elements in the flow content objects.
By default, the creates a as parent for structure elements defined by the flow content objects. This element is a direct child of the structure element which represents the document and is the root of the structure tree.
The new parent applies only to flow content objects added to the document after this property has been set.
The structure element used as parent must be included explicitly in the document's structure tree.

public PDFStructureElement getParentStructureElementForContent()