Hiding notes

In the following examples, some notes are hidden: although they are made transparent, they still take vertical and horizontal space.

\version "2.24"

%% http://lsr.di.unimi.it/LSR/Item?id=418


\relative c'' {
  c4 d
  \hideNotes
  e  f
  \unHideNotes
  g  a
  \once\hideNotes
  b
  c
}