I'm trying to make a formula and I got the error: $ operator not defined for this S4 class with R. First of all, what is a S4 class? What am I doing wrong
svelte-testing-library
html5-history
multiline
generic-list
maven-release-plugin
android-displaycutout
decimal
system-verilog-dpi
comexception
mastodon
go-ent
typo3-surf
drawrect
data-science
pyvista
flutter-test
traffic
cypress-cucumber-preprocessor
bond
floating-point-conversion
nm
compose-multiplatform
ibm-case-manager
nao-robot
application-security
upsetr
installation-package
delegation
ramda.js
lld
