'Get usage for all tenants
:param start: :class:`datetime.datetime` Start date in UTC
:param end: :class:`datetime.datetime` End date in UTC
:param detailed: Whether to include information about each
instance whose usage is part of the report
:param marker: Begin returning usage data for instances that appear
later in the instance list than that represented by
this instance UUID (optional).
:param limit: Maximum number of instances to include in the usage
(optional).
:rtype: list of :class:`Usage`.'

@api_versions.wraps('2.40')
def list(self, start, end, detailed=False, marker=None, limit=None):

    query_string = self._usage_query(start, end, marker, limit, detailed)
    url = ('/%s%s' % (self.usage_prefix, query_string))
    return self._list(url, 'tenant_usages')
