July / August 2023: 

Leaving out the SVAR_estimate() call (which is a user error, of course) causes
a cryptic and thus "nasty" error message from gretl about unknown objects.
So we probably need to re-insert some checks at the bootstrapping or similar 
stages whether estimation has taken place, and print out meaningful messages.

(We decided to postpone this to after 2023b.) 
