rubocop.txt

$ rubocop --only Lint/UnusedMethodArgument unused.rb 
Inspecting 1 file
W

Offenses:

unused.rb:1:9: W: [Correctable] Lint/UnusedMethodArgument: Unused method argument - bar. If it's necessary, use _ or _bar as an argument name to indicate that it won't be used. If it's unnecessary, remove it. You can also write as foo(*) if you want the method to accept any arguments but don't care about them.
def foo(bar, baz: 1)
        ^^^
unused.rb:1:14: W: Lint/UnusedMethodArgument: Unused method argument - baz. You can also write as foo(*) if you want the method to accept any arguments but don't care about them.
def foo(bar, baz: 1)
             ^^^

1 file inspected, 2 offenses detected, 1 offense autocorrectable

unused.rb

def foo(bar, baz: 1)
  1 + 1
end