This document is a checklist for adding / changing parameters to find_embedding,
because, as you'll see, it's gotten to be a fairly tedious process.

1) include/util.hpp:
  [ ] member declaration (with default) of the `optional_parameters` class
  [ ] component constructor in the `optional_parameters` class
  [ ] optional -- create exceptions involving bad values etc.

2) minorminer/_minorminer_h.pxi:
  [ ] member declaration of the `optional_parameters` class

3) minorminer/_minorminer.pyx:
  [ ] document the parameter (with default) in the docstring of `find_embedding`
  [ ] add the parameter to the set `names`
  [ ] populate and cast the parameter found in `params`

4) minorminer/minorminer.py:
  [ ] add the parameter (with default) to the wrapper function signature
  [ ] pass the parameter to `minorminer_c.find_embedding`

5) matlab/find_embedding.cpp:
  [ ] insert parameter name to `paramNameSet`
  [ ] add populate and cast the parameter found in `findEmbeddingExternalParams`

6) matlab/find_embedding.m:
  [ ] document the parameter (with default) in the comment block

7) tests/test_lib.py:
  [ ] add tests excercising the parameter
  [ ] optional -- if the parameter imposes checkable constraints on the input,
    add it to check_args
  [ ] optional -- if the parameter imposes checkable constraints on the output,
    add it to check_embedding
