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: sql_base.rb
    path of file: ./repos/boxcars/lib/boxcars/boxcar
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

# Boxcars is a framework for running a series of tools to get an answer to a question.
module Boxcars
  # A Boxcar that interprets a prompt and executes SQL code to get answers
  # Use one of the subclasses for ActiveRecord or Sequ
    
    def clean_up_output(code)
      output = get_output(code)
      output = output.as_json if output.is_a?(::ActiveRecord::Result)
      output = 0 if output.is_a?(Array) && output.empty?
      output = output.first if output.is_a?(Array) && output.length == 1
      output = output[output.keys.first] if output.is_a?(Hash) && output.length == 1
      output = output.as_json if output.is_a?(::ActiveRecord::Relation)
      output
    end