class SyntaxTree::YieldNode

def format(q)
  if arguments.nil?
    q.text("yield")
    return
  end
  q.group do
    q.text("yield")
    if arguments.is_a?(Paren)
      q.format(arguments)
    else
      q.if_break { q.text("(") }.if_flat { q.text(" ") }
      q.indent do
        q.breakable_empty
        q.format(arguments)
      end
      q.breakable_empty
      q.if_break { q.text(")") }
    end
  end
end