Fix SpectrumDatasetOnOff.plot_counts docstring
@@ -330,6 +330,7 @@ class SpectrumDatasetOnOff(Dataset):
-------
ax : `~matplotlib.pyplot.Axes`
Axes object.
+
"""
import matplotlib.pyplot as plt
@@ -359,6 +360,7 @@ class SpectrumDatasetOnOff(Dataset):
-------
ax : `~matplotlib.pyplot.Axes`
Axes object.
+
"""
import matplotlib.pyplot as plt
