bless $ ref , [ classname ]
Looks up the item pointed to by reference
ref
and tells the item that it is now an object in the
classname
package - or the current package if no
classname
is specified. It returns the reference for convenience, since a
bless
is often the last thing in a constructor function. (Always use the two-argument version if the constructor doing the blessing might be inherited by a derived class. In such cases, the class you want to bless your object into will normally be found as the first argument to the constructor in question.)