Dispatches to the specific visit method for this MIME body part.
This default implementation for MailKit.BodyPart nodes calls MailKit.BodyPartVisitor.VisitBodyPart. Override this method to call into a more specific method on a derived visitor class of the MailKit.BodyPartVisitor class. However, it should still support unknown visitors by calling MailKit.BodyPartVisitor.VisitBodyPart.