+
+ validates_length_of :k, :within => 1..255
+ validates_length_of :v, :within => 1..255
+
+ # Turn this Node in to an XML Node without the <osm> wrapper.
+ def to_xml_node
+ el1 = XML::Node.new 'preference'
+ el1['k'] = self.k
+ el1['v'] = self.v
+
+ return el1
+ end
+