def validated_attr_accessor(symbols, validator)
        symbols.each do |symbol|
          attr_reader symbol
          module_eval(SETTER % [symbol, validator, symbol], __FILE__, __LINE__)
        end
      end
Creates the reader and writer access methods
@param [Array] symbols The names of the attributes to create
@param [String] validator The axlsx validation method to use when
validating assignation.
@see lib/axlsx/util/validators.rb