def test_step_scan():
# use __getitem__
columns = ['Tsam', 'point_det', 'time']
df = StepScan[-1]
assert_equal(set(df.columns), set(columns))
assert_equal(len(df), 3)
# use find_headers
df = StepScan.find_headers(data_key='Tsam')
assert_equal(set(df.columns), set(columns))
assert_equal(len(df), 3)
def test_no_results():
df = StepScan.find_headers(owner='no one')
assert_equal(len(df), 0)
