A wrapper around a DDF (Escher) EscherTextbox Record. Causes the DDF
Record to be accessible as if it were a HSLF record.
Note: when asked to write out, will simply put any child records correctly
into the Escher layer. A call to the escher layer to write out (by the
parent PPDrawing) will do the actual write out
Returns the underlying DDF Escher Record
Creates the wrapper for the given DDF Escher Record and children
Creates a new, empty wrapper for DDF Escher Records and their children
Return the type of the escher record (normally in the 0xFnnn range)
Stores the data for the child records back into the Escher layer.
Doesn't actually do the writing out, that's left to the Escher
layer to do. Must be called before writeOut/serialize is called
on the underlying Escher object!