def load(self, filename, create_if_missing=True):
        filename = Path(filename)
        if not filename.exists() and create_if_missing:
            self.load_pip_requirements()
            with filename.open("w") as f:
                f.write(yaml.dump(self.serialized, default_flow_style=False,
                                  encoding=None))
            self.filename = filename
            return self.save(filename)
        with filename.open() as f:
            for group, requirements in yaml.load(f.read()).items():
                for requirement in requirements:
                    self[group].add(Requirement.coerce(requirement))
        self.filename = filename
def get(self, section, option):
            if _section == section:
                if option == 'memcache_servers':
                    if _srvs == 'error':
                        raise NoOptionError(option, section)
                    return _srvs
                elif option == 'memcache_serialization_support':
                    if _sers == 'error':
                        raise NoOptionError(option, section)
                    return _sers
                elif option in ('memcache_max_connections',
                                'max_connections'):
                    if _maxc == 'error':
                        raise NoOptionError(option, section)
                    return _maxc
                else:
                    raise NoOptionError(option, section)
            else:
                raise NoSectionError(option)