⌂ Suppressing warnings for clashing note columns

If notes from two voices with stems in the same direction are placed at the same position, and both voices have no shift or the same shift specified, the error message warning: ignoring too many clashing note columns will appear when compiling the LilyPond file. This message can be suppressed by setting the 'ignore-collision property of the NoteColumn object to #t. Please note that this does not just suppress warnings but stops LilyPond trying to resolve collisions at all and so may have unintended results unless used with care.