code: def _get_exe(prog):
          '''Given a program name, return what we expect its exectuable to be called'''
          if prog in prog_to_env_var:
              env_var = prog_to_env_var[prog]
              if env_var in os.environ:
                  return os.environ[env_var]
  
          return prog_to_default[progf _get_exe(prog):
          '''Given a program name, return what we expect its exectuable to be called'''
          if prog in prog_to_env_var:
              env_var = prog_to_env_var[prog]
              if env_var in os.environ:
                  return os.environ[env_var]
  
          return prog_to_default[prog]
docs: Given a program name, return what we expect its exectuable to be called