doc: remove class definition from Expressions sample

doc/sample/Expressions.im

@@ -59,69 +59,6 @@ z = do
     ^x + y
 end.
 
-class Person
-    /**
-        every message handler can have one or both of the following:
-        - a message name (in this case, 'init')
-        - a set of one or more parameters (wrapped in parentheses if the message
-          has a name)
-
-        each parameter has an internal name and an (optional) label, specified
-        as a pair of identifiers separated by a colon (:). the label comes
-        first, and is the name used by whoever is sending the message the
-        internal name comes second, and is used by the message handler itself as
-        a variable name.
-
-        you can omit the label for a parameter by specifying an underscore (_)
-        as the label, but this is not recommended. it looks weird, it obscures
-        the meaning of the message, and is really only supported for
-        compatibility with lambdas.
-    **/
-    - init(name:name age:age)
-        self::name = name.
-        self::age = age!
-
-    - test(param:data _:extra) | cout put:'Received {data}, {extra}'.
-
-    - name | ^self::name.
-
-    - age | ^self::age.
-
-    - ageInMonths | ^self::age * 12.
-
-    - setName:name | self::name = name.
-
-    - setAge:age | self::age = age.
-
-    - setAge:age inUnit:units
-        match units in
-            #years  => self::age = age,
-            #months => self::age = age / 12,
-            #days   => self::age = age / 365,
-            _       => self::age = 0
-        end!
-
-    - getAgeInUnit:units
-        ^match units in
-            #years  => self::age,
-            #months => self::age / 12,
-            #days   => self::age / 365,
-            _       => 0
-        end!
-
-    $ exampleProperty | get => self::val, set => self::val = value.
-
-    $ exampleProperty2 |
-        get => [ ^self::val ],
-        set => [ :x | self::val = x ].
-
-    $ exampleProperty3 | get => 42.
-
-    $ exampleProperty4 (get, set)
-
-    $ exampleProperty5 (get)
-end
-
 j = [ cout put:'Hello!' ].
 k = [ :x :y | cout put:'Hello, {x}, {y}!' ].