'List version objects within a bucket.  This returns an
instance of an VersionedBucketListResultSet that automatically
handles all of the result paging, etc. from S3.  You just need
to keep iterating until there are no more results.  Called
with no arguments, this will return an iterator object across
all keys within the bucket.
:type prefix: string
:param prefix: allows you to limit the listing to a particular
prefix.  For example, if you call the method with
prefix=\'/foo/\' then the iterator will only cycle through
the keys that begin with the string \'/foo/\'.
:type delimiter: string
:param delimiter: can be used in conjunction with the prefix
to allow you to organize and browse your keys
hierarchically. See:
http://aws.amazon.com/releasenotes/Amazon-S3/213
for more details.
:type key_marker: string
:param key_marker: The "marker" of where you are in the result set
:param encoding_type: Requests Amazon S3 to encode the response and
specifies the encoding method to use.
An object key can contain any Unicode character; however, XML 1.0
parser cannot parse some characters, such as characters with an
ASCII value from 0 to 10. For characters that are not supported in
XML 1.0, you can add this parameter to request that Amazon S3
encode the keys in the response.
Valid options: ``url``
:type encoding_type: string
:rtype: :class:`boto.s3.bucketlistresultset.BucketListResultSet`
:return: an instance of a BucketListResultSet that handles paging, etc'

def list_versions(self, prefix='', delimiter='', key_marker='', version_id_marker='', headers=None, encoding_type=None):

    return VersionedBucketListResultSet(self, prefix, delimiter, key_marker, version_id_marker, headers, encoding_type=encoding_type)
