$ python
Python 3.4.3 (default, Jul 28 2015, 18:20:59) 
[GCC 4.8.4] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import logging
>>> logger = logging.getLogger('revscoring')
>>> logger.setLevel(logging.DEBUG)
>>> import revscoring
>>> from revscoring.dependencies import solve
>>> from revscoring.features import wikitext
>>> from revscoring.datasources import revision_oriented as ro
>>> solve(wikitext.revision.templates, cache={ro.revision.text: "foo {{bar}} derp"})
DEBUG:revscoring.dependencies.dependent:Executing datasource.wikitext.revision.wikicode (0 calls so far).
DEBUG:revscoring.dependencies.dependent:Executing datasource.wikitext.revision.node_class_map (0 calls so far).
DEBUG:revscoring.dependencies.dependent:Executing datasource.wikitext.revision.templates (0 calls so far).
DEBUG:revscoring.dependencies.dependent:Executing feature.wikitext.revision.templates (0 calls so far).
1
>>> cache = {ro.revision.text: "foo {{bar}} derp"}
>>> solve(wikitext.revision.templates, cache=cache)
DEBUG:revscoring.dependencies.dependent:Executing datasource.wikitext.revision.wikicode (1 calls so far).
DEBUG:revscoring.dependencies.dependent:Executing datasource.wikitext.revision.node_class_map (1 calls so far).
DEBUG:revscoring.dependencies.dependent:Executing datasource.wikitext.revision.templates (1 calls so far).
DEBUG:revscoring.dependencies.dependent:Executing feature.wikitext.revision.templates (1 calls so far).
1
>>> cache
{<feature.wikitext.revision.templates>: 1, <datasource.wikitext.revision.templates>: ['{{bar}}'], <datasource.wikitext.revision.wikicode>: 'foo {{bar}} derp', <datasource.wikitext.revision.node_class_map>: {<class 'mwparserfromhell.nodes.text.Text'>: ['foo ', 'bar', ' derp'], <class 'mwparserfromhell.nodes.template.Template'>: ['{{bar}}']}, <datasource.revision.text>: 'foo {{bar}} derp'}
>>> solve(wikitext.revision.templates, cache=cache)
1