def install_bower(self, package, save=True, save_dev=False):
        """Installs a bower 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 list of tuples, containing all installed package names
            and versions, including any dependencies.
        """
        requirement = Requirement.coerce(package)
        url = Bower.get_package_url(requirement.package)

        installed = []
        for name, _ in self.get_bower_package(url):
            installed.append(Requirement(name, requirement.version))

        for requirement in installed:
            if save:
                self.requirements["bower"].add(requirement, replace=True)
            if save_dev:
                self.requirements["bower-dev"].add(requirement, replace=True)
            success("installed {}".format(str(requirement)))
        if save or save_dev:
            self.requirements.save()
        return installed
def _testrefastpath(repat):
    """Test if a re pattern can use fast path.

    That is, for every "$A/$B" path the pattern matches, "$A" must also be
    matched,

    Return True if we're sure it is. Return False otherwise.
    """
    # XXX: It's very hard to implement this. These are what need to be
    # supported in production and tests. Very hacky. But we plan to get rid
    # of re matchers eventually.

    # Rules like "(?!experimental/)"
    if repat.startswith("(?!") and repat.endswith(")") and repat.count(")") == 1:
        return True

    # Rules used in doctest
    if repat == "(i|j)$":
        return True

    return False