def select
      new_instance = self.class.new
      if block_given?
        @data.each { |k,v| new_instance.data[k] = v if yield(k,v) }
      end
      return new_instance
    end
def select
      new_instance = self.class.new
      if block_given?
        @data.each { |k,v| new_instance.data[k] = v if yield(k,v) }
      end
      return new_instance
    end
Returns a new instance consisting of entries for which the block returns
 true. Not that an enumerator is not available for the OrderedHash'
 implementation