@environmentfilter
def do_first(environment, seq):
    try:
        return iter(seq).next()
    except StopIteration:
        return environment.undefined('No first item, sequence was empty.')
Make a L{ProxyClient} object used for testing.
dataset/ETHPy150Open IanLewis/kay/kay/lib/jinja2/filters.py/do_first--crossover with--dataset/ETHPy150Open kuri65536/python-for-android/python-modules/twisted/twisted/web/test/test_proxy.py/ProxyClientTestCase.makeProxyClient