def METHOD_NAME(bla):
    """
    TESTS::
        sage: from sage.structure.list_clone_timings import *
        sage: add1_mutable(IncreasingArrays()([1,4,5]))
        [2, 5, 6]
    """
    blo = bla.__copy__()
    for i in range(len(blo)):
        blo[i] += 1
    blo.set_immutable()
    blo.check()
    return blo