You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: ruby.rb
    path of file: ./repos/steep/lib/steep/diagnostic
    
    the code of the file until where you have to start completion: module Steep
  module Diagnostic
    module Ruby
      class Base
        include Helper

        attr_reader :node
        attr_reader :location

        def initialize(node:, location: node&.location&.expression)
          @node = node
          @location = location
        end

        def header_line
          error_name
        end

        def de
    
        def detail_lines
          lines = StringIO.new.tap do |io|
            failure_path = result.failure_path || []
            failure_path.reverse_each.map do |result|
              relation_message(result.relation)
            end.compact.each.with_index(1) do |message, index|
              io.puts "#{"  " * (index)}#{message}"
            end
          end.string.chomp

          unless lines.empty?
            lines
          end
        end
      end