The InDocumentOrder operator can be called on a sequence of nodes and returns a sequence containing each source node's child nodes in document order.
The InDocumentOrder operator has one prototype.
public static IEnumerable<T> InDocumentOrder<T> ( this IEnumerable<T> source ) where T : XNode
This version is called on a sequence of a specified type, which must be nodes or some type derived from nodes, and returns a sequence of that same type containing each source node's child nodes in document order.
This is a fairly odd operator. For this example, I need a source sequence of nodes. Since I want to see some nodes that are not elements in addition to elements, ...