define caldb in docstring example
@@ -190,6 +190,8 @@ class DataStore:
This is how you can access a single event list::
>>> from gammapy.data import DataStore
+ >>> import os
+ >>> os.environ["CALDB"] = os.environ["GAMMAPY_DATA"] + "/cta-1dc/caldb"
>>> path = "$GAMMAPY_DATA/cta-1dc/data/baseline/gps/gps_baseline_110380.fits"
>>> data_store = DataStore.from_events_files([path])
>>> observations = data_store.get_observations()
