def inspect
      attrs = []
      attrs << ['key', @key.inspect] unless @key.nil?
      attrs << ['value', @value.inspect] unless @value.nil?
      model.attributes.map do |attr, default|
        val = read_attribute(attr)
        attrs << [attr.to_s, val.inspect] unless val.nil?
      end
      attrs.sort!
      attrs.unshift([:id, id]) unless new?
      sprintf('#<%s %s>', model, attrs.map { |a| a.join(': ') }.join(', '))
    end
def inspect
      attrs = []
      attrs << ['key', @key.inspect] unless @key.nil?
      attrs << ['value', @value.inspect] unless @value.nil?
      model.attributes.map do |attr, default|
        val = read_attribute(attr)
        attrs << [attr.to_s, val.inspect] unless val.nil?
      end
      attrs.sort!
      attrs.unshift([:id, id]) unless new?
      sprintf('#<%s %s>', model, attrs.map { |a| a.join(': ') }.join(', '))
    end
@private Returns a string containing a human-readable representation
 of the record.

 @since 0.0.1