class RuboCop::Cop::Style::MethodDefParentheses

def on_def(node)
  return if forced_parentheses?(node)
  args = node.arguments
  if require_parentheses?(args)
    if arguments_without_parentheses?(node)
      missing_parentheses(node)
    else
      correct_style_detected
    end
  elsif parentheses?(args)
    unwanted_parentheses(args)
  else
    correct_style_detected
  end
end