gistfile1.txt

class FairSummaryJson
  def initialize(fair, options={})
    @cash_report_url = options.fetch(:cash_report_url) { '' }
  end

  def to_hash
    {
      id: fair.id,
      school: SchoolSummaryJson.new(fair.school).to_hash
      cash_report_url: cash_report_url
    }
  end
end

def FairDetailJson
  ...
end

def SchoolSummaryJson
  def initialize(school)
    @school = school
  end

  def to_hash
    {
      id: school.id
      name: school.name
    }
  end
end