def has_single_provenance(provenance_list):
    """ Checks whether the collection is all from the same source
    Runtime: O(n)

    Arguments:
    provenance_list -- list of Glucose-related objects with
                provenance_identifier property

    Output:
    True if the samples are from same source
    """
    try:
        first_provenance = provenance_list[0]
    except IndexError:
        print("Out of bounds error: list doesn't contain objects")
    for provenance in provenance_list:
        if provenance != first_provenance:
            return False
    return True
