'Create a new volume.
:param size: Size of volume in gigabytes (required)
:type size: ``int``
:param name: Name of the volume to be created
:type name: ``str``
:param location: Which data center to create a volume in. If
empty, undefined behavior will be selected.
(optional)
:type location: :class:`.NodeLocation`
:param snapshot:  Snapshot from which to create the new
volume.  (optional)
:type snapshot: :class:`.VolumeSnapshot`
:return: The newly created volume.
:rtype: :class:`StorageVolume`'

def create_volume(self, size, name, location=None, snapshot=None):

    raise NotImplementedError('create_volume    not    implemented    for    this    driver')
