[ Version ( since = "3.60" ) ]
public void write_attr (VCardVersion to_version, VCardAttribute destination)
Populates the destination with the data from the this, using format suitable to
to_version vCard version.
The function does nothing when the this is an empty structure. The destination is
supposed to be a KEY attribute.
| this |
an ContactCert |
| to_version |
one of VCardVersion |
| destination |
a destination VCardAttribute |