Gets the System.Xml.XmlImplementation object for the current document.
System.Xml.XmlImplementation object which created this object, or null if there is no such relevant object.
XmlDocument objects created from the same XmlImplementation share the same System.Xml.XmlNameTable. This allows users to compare attribute and element names as objects rather than strings.
Although the XmlDocument objects share the same implementation, to move nodes from one document to another you must use the XmlDocument.ImportNode(XmlNode, bool) method.