Don't fail on large requests about etcd3-py HOT 9 OPEN

range('/foo/', prefix=True)

# Is equal to

range('/foo/a', range_end='/foo/b')
range('/foo/b', range_end='/foo/c')
range('/foo/d, range_end='/foo/e')
...
range('/foo/y', range_end='/foo/z')

limit = 1000
range_end = incr_last_byte(prefix)
prefix_start = prefix
done = False
result = []
while not done:
    subrange = range(prefix_start, range_end=range_end, limit=limit)
    result.append(subrange.kvs[:-1])
    done = prefix_start == subrange.kvs[-1].key
    prefix_start = subrange.kvs[-1].key
return result

async def big_range(
    kvapi,
    key=None,
    range_end=None,
    limit=1000,
    revision=None,
    keys_only=False,
    serializable=False,
    min_mod_revision=None,
    max_mod_revision=None,
    min_create_revision=None,
    max_create_revision=None,
    sort_order=models.RangeRequestSortOrder.NONE,
    sort_target=models.RangeRequestSortTarget.KEY,
    prefix=False,
    all=False
    ):
    method = '/kv/range'
    if all:
        key = range_end = '\0'
    if prefix:
        range_end = incr_last_byte(key)
    data = {
        "key": key,
        "range_end": range_end,
        "limit": limit,
        "revision": revision,
        "sort_order": sort_order,
        "sort_target": sort_target,
        "serializable": serializable,
        "keys_only": keys_only,
        "count_only": None,
        "min_mod_revision": min_mod_revision,
        "max_mod_revision": max_mod_revision,
        "min_create_revision": min_create_revision,
        "max_create_revision": max_create_revision
    }
    data = {k: v for k, v in data.items() if v is not None}
    result = subrange = await kvapi.call_rpc(method, data=data)
    if not result.kvs: return result
    subrange = result
    while len(subrange.kvs) == limit:
        data['key'] = subrange.kvs[-1].key
        subrange = await kvapi.call_rpc(method, data=data)
        result.kvs.extend(subrange.kvs[1:])
        if 'revision' not in data:
            data['revision'] = subrange.header.revision
    return result

class Ranger:
    def __init__(...):
        self.start
        self.current = start
        self.buf
        self.end
        self.limit
        self.finished

    def range() -> returns a iterator
           while current < end:
                  buf = client.range(current, end, limit)
                  if not buf.kvs:
                         break
                  for pair in buf.kvs:
                        self.current = pair.key
                        yield pair
                  current += 1
           self.finished = true