def get_feature_types(self, ctx, ref):
"""
Retrieve the list of Feature types.
@return List of feature type identifiers (strings)
:param ref: instance of type "ObjectReference"
:returns: instance of list of String
"""
# ctx is the context object
# return variables are: returnVal
#BEGIN get_feature_types
ga = GenomeAnnotationAPI_local(self.services, ctx['token'], ref)
returnVal = ga.get_feature_types()
#END get_feature_types
# At some point might do deeper type checking...
if not isinstance(returnVal, list):
raise ValueError('Method get_feature_types return value ' +
'returnVal is not type list as required.')
# return the results
return [returnVal]
