def data_for_cities( cities )
    ## fix: move to model? why? why not?
    
    ## add virtual column like kind for metro, metro|city, city, district
  
    ## todo add region.title if present  
  
    data = []
    cities.each do |city|
      data << { key:      city.key,
                title:    city.title,
                code:     city.code,
                pop:      city.pop,
                popm:     city.popm,
                area:     city.area,
                synonyms: city.synonyms,
                country:  city.country.title }      
    end # each city
    data
  end
def data_for_cities( cities )
    ## fix: move to model? why? why not?
    
    ## add virtual column like kind for metro, metro|city, city, district
  
    ## todo add region.title if present  
  
    data = []
    cities.each do |city|
      data << { key:      city.key,
                title:    city.title,
                code:     city.code,
                pop:      city.pop,
                popm:     city.popm,
                area:     city.area,
                synonyms: city.synonyms,
                country:  city.country.title }      
    end # each city
    data
  end
=begin
  def csv_content_type
    case request.user_agent
    when /windows/i then 'application/vnd.ms-excel'
    else                 'text/csv'
    end
  end
=end