Is the "-rN" option implemented?

[nickleroy]

According to "README.md", the "-rN" option: "repeat thumbnail generation each N seconds, N=0 means disable repetition (default: 0)". However, in main.cpp, the call to getopt() includes "r:", but the parser itself does not handle the option. Is it just plain not implemented? There appears to be no other reference to the word "repeat" in the source.