def metadata
      warn 'metadata is deprecated. Use column_properties[] instead'
      @column_properties.inject({}){|res, (k, v)| res.merge!({k => v.to_h})}
    end
def metadata
      warn 'metadata is deprecated. Use column_properties[] instead'
      @column_properties.inject({}){|res, (k, v)| res.merge!({k => v.to_h})}
    end
Returns meta data as Hash with header name as key