Removed old ComputedAttribute.py

lib/Components/ExtensionClass/ComputedAttribute.py

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-############################################################################## 
-__doc__='''Sample application of the '__of__' protocol, computed attributes
-
-It is not uncommon to wish to expose information via the attribute 
-interface without exposing implementation.  In principle, one can 
-use a custom '__getattr__' method to implement computed attributes,
-however, this can be a bit cumbersome and can interfere with other
-uses of '__getattr__', such as for persistence.
-
-The '__of__' protocol provided by ExtensionClass provides another way
-of implementing computed attribute.  The of '__of__' protocol provides
-a way of returning sub-objects in the context of a container.  For
-example::
-
-   x.__of__(y)
-
-should be interpreted as "compute y in the context of x".  When 
-getting an ExtensionClass attribute, the attributes '__of__' method is
-called automatically, if it has one.
-
-This module provides a simple computed attribute implementation and
-an example of its usage.
-
-$Id: ComputedAttribute.py,v 1.2 1998/12/04 20:57:46 jim Exp $'''
-__version__='$Revision: 1.2 $'[11:-2]
-
-import ExtensionClass
-
-class ComputedAttribute(ExtensionClass.Base):
-
-    def __init__(self, func): self.func=func
-
-    def __of__(self, parent): return self.func(parent)
-
-############################################################################## 
-# Test code:
-#
-
-if __name__ == "__main__":
-
-    from math import sqrt
-
-    class point(ExtensionClass.Base):
-
-        def __init__(self, x, y): self.x, self.y = x, y
-
-        radius=ComputedAttribute(lambda self: sqrt(self.x**2+self.y**2))
-
-    p=point(2,2)
-    print p.radius