use constant STEPPER_SEQUENCE => [
    [qw(1 0 0 1)],
    [qw(1 0 0 0)],
    [qw(1 1 0 0)],
    [qw(0 1 0 0)],
    [qw(0 1 1 0)],
    [qw(0 0 1 0)],
    [qw(0 0 1 1)],
    [qw(0 0 0 1)],
];