Contact Writer
Responsible for converting the Contact data class (which is not version-specific) to the vCard that is actually sent to the server.
Properties which are not supported by the target vCard version have to be converted appropriately.
Parameters
contact
contact data to be converted into a vCard
version
vCard version to generate
product Id
product ID that identifies your app (will be used as PRODID; ez-vcard version will be appended)