def _get_tiles(board=None, terrain=None, numbers=None):
if board is not None:<EOL><INDENT>tiles = _read_tiles_from_string(board)<EOL><DEDENT>else:<EOL><INDENT>tiles = _generate_tiles(terrain, numbers)<EOL><DEDENT>return tiles<EOL>
Generate a list of tiles using the given terrain and numbers options.

terrain options supported:
- Opt.empty -> all tiles are desert
- Opt.random -> tiles are randomized
- Opt.preset ->
- Opt.debug -> alias for Opt.random

numbers options supported:
- Opt.empty -> no tiles have numbers
- Opt.random -> numbers are randomized
- Opt.preset ->
- Opt.debug -> alias for Opt.random

:param terrain_opts: Opt
:param numbers_opts: Opt
:return: list(Tile)