# File lib/codec/mapping.rb, line 42
      def initialize(code, name, klasses = nil, getter = nil)

        @code = code
        @name = name

        @@by_code[code] = self

        unless klasses.nil?
          klasses.each do |klass|
            raise "entry exists for #{klass}" if @@by_class.keys.include? klass
            @@by_class[klass] = self unless klass.nil?
          end
        end

        @put_method = (name + "=").intern

        if getter.nil?
          @get_method = name.intern
        else
          @get_method = getter.intern
        end
      end