class RuboCop::Cop::Gemspec::RequiredRubyVersion

def investigate(processed_source)
  required_ruby_version(processed_source.ast) do |version|
    ruby_version = extract_ruby_version(version)
    return if ruby_version == target_ruby_version.to_s
    add_offense(
      processed_source.ast,
      location: version.loc.expression,
      message: message(ruby_version, target_ruby_version)
    )
  end
end