class RSpec::Mocks::ArgumentListMatcher

def ensure_expected_args_valid!
  if expected_args.count { |a| ArgumentMatchers::AnyArgsMatcher::INSTANCE == a } > 1
    raise ArgumentError, "`any_args` can only be passed to " \
          "`with` once but you have passed it multiple times."
  elsif expected_args.count > 1 && expected_args.any? { |a| ArgumentMatchers::NoArgsMatcher::INSTANCE == a }
    raise ArgumentError, "`no_args` can only be passed as a " \
          "singleton argument to `with` (i.e. `with(no_args)`), " \
          "but you have passed additional arguments."
  end
end