'Internal helper called to tell the property its name.
This is called by _fix_up_properties() which is called by
MetaModel when finishing the construction of a Model subclass.
The name passed in is the name of the class attribute to which the
Property is assigned (a.k.a. the code name).  Note that this means
that each Property instance must be assigned to (at most) one
class attribute.  E.g. to declare three strings, you must call
StringProperty() three times, you cannot write
foo = bar = baz = StringProperty()'

def _fix_up(self, cls, code_name):

    self._code_name = code_name
    if (self._name is None):
        self._name = code_name
