This Readme file explains the structure of the Demeter::StructuralUnit
serialization.  The serialization file is a normal zip file with the
"dsu" extension (_D_emeter _s_tructural _u_nit).

A structural unit is a collection of Demeter objects which implement a
conceptual component of a fit.  In a script or a GUI, a structural
unit is defined as a selection of paths.  Contained in this zip file
are serializations of a number of Path objects, the Feff objects from
which those paths were computed, and all GDS objects referenced by the
Path's math expressions.

The serializations of the Path, Feff, and GDS objects are YAML files.
Also contained herein are the phase.bin files associated with the Feff
objects.