'Return a dictionary containing meter statistics.
Meter statistics is described by the query parameters.
The filter must have a meter value set.
{ \'min\':
\'max\':
\'avg\':
\'sum\':
\'count\':
\'period\':
\'period_start\':
\'period_end\':
\'duration\':
\'duration_start\':
\'duration_end\':'

def get_meter_statistics(self, sample_filter, period=None, groupby=None, aggregate=None):

    return []
