3. lib: Libraries
3.1. lib.fdtd: FDTD
3.2. lib.backend
3.3. lib.boson: Boson classes
This module contains the definition of the Boson
superclass and subclasses: Photon,
Phonon (WIP, not implemented).
3.3.1. Dipole/quadrupole moment functions
3.3.2. Boson class definition
Boson is largely a template class, functionality meant to
be implemented within subclasses.