def get_historical_usage_metrics(self, webspace_name, website_name,<EOL>metrics = None, start_time=None, end_time=None, time_grain=None):
metrics = ('<STR_LIT>'+'<STR_LIT:U+002C>'.join(metrics)) if metrics else '<STR_LIT>'<EOL>start_time = ('<STR_LIT>'+start_time) if start_time else '<STR_LIT>'<EOL>end_time = ('<STR_LIT>'+end_time) if end_time else '<STR_LIT>'<EOL>time_grain = ('<STR_LIT>'+time_grain) if time_grain else '<STR_LIT>'<EOL>parameters = ('<STR_LIT:&>'.join(v for v in (metrics, start_time, end_time, time_grain) if v))<EOL>parameters = '<STR_LIT:?>'+parameters if parameters else '<STR_LIT>'<EOL>return self._perform_get(self._get_historical_usage_metrics_path(webspace_name, website_name) + parameters,<EOL>MetricResponses)<EOL>
Get historical usage metrics.

webspace_name:
    The name of the webspace.
website_name:
    The name of the website.
metrics:
    Optional. List of metrics name. Otherwise, all metrics returned.
start_time:
    Optional. An ISO8601 date. Otherwise, current hour is used.
end_time:
    Optional. An ISO8601 date. Otherwise, current time is used.
time_grain:
    Optional. A rollup name, as P1D. OTherwise, default rollup for the metrics is used.
More information and metrics name at:
http://msdn.microsoft.com/en-us/library/azure/dn166964.aspx