def test_accumulate__end_date(padding,sample_key,delta):
sd = sample_data[sample_key]
ts = TimeSeries(sd)
original_len = len(ts.data)
ts.accumulate(delta,"Day",padding=padding)
assert(ts.get_x()[-1]==expected_end_date(sd[-1][0],delta,original_len,padding))
def test_accumulate__empty():
#It should be possible to initialize with an empty list
ts = TimeSeries([])
ts.accumulate(2)
assert(ts.data==[])
def test_accumulate__steps(padding,sample_key,delta):
ts = TimeSeries(sample_data[sample_key])
ts.accumulate(delta,"Day",padding=padding)
for i in range(1,len(ts.data)):
assert((ts.data[i][0]-ts.data[i-1][0]).days == delta)