def install_pip(self, package, save=True, save_dev=False):
        """Installs a pip package.

        :param save: if `True`, pins the package to the Hydrogen requirements
            YAML file.
        :param save_dev: if `True`, pins the package as a development
            dependency to the Hydrogen requirements YAML file.
        :param return: a **single** :class:`Requirement` object, representing
            the installed version of the given package.
        """
        requirement = Requirement.coerce(package)
        click.echo("pip install " + requirement.package)
        cmd = envoy.run("pip install {}".format(str(requirement)))
        if cmd.status_code == 0:
            installed_packages = get_installed_pypackages()
            package = installed_packages[requirement.package]
            requirement.version = "=={}".format(package.version)
            if save:
                self.requirements["all"].add(requirement)
            if save_dev:
                self.requirements["dev"].add(requirement)
            if save or save_dev:
                self.requirements.save()
            return requirement
        else:
            fatal(cmd.std_err)
def test_contructor_updates_state_shema_in_change_cmd(self):
        score_category = (
            suggestion_models.SCORE_TYPE_QUESTION +
            suggestion_models.SCORE_CATEGORY_DELIMITER + 'skill_id')
        change = {
            'cmd': (
                question_domain
                .CMD_CREATE_NEW_FULLY_SPECIFIED_QUESTION),
            'question_dict': {
                'question_state_data': self.VERSION_27_STATE_DICT,
                'question_state_data_schema_version': 27,
                'language_code': 'en',
                'linked_skill_ids': ['skill_id'],
                'inapplicable_skill_misconception_ids': []
            },
            'skill_id': 'skill_id',
            'skill_difficulty': 0.3
        }
        self.assertEqual(
            change['question_dict']['question_state_data_schema_version'], 27)

        suggestion = suggestion_registry.SuggestionAddQuestion(
            'suggestionId', 'target_id', 1, suggestion_models.STATUS_IN_REVIEW,
            self.author_id, None, change, score_category, 'en', False,
            self.fake_date)
        self.assertEqual(
            suggestion.change.question_dict[
                'question_state_data_schema_version'],
            feconf.CURRENT_STATE_SCHEMA_VERSION)