Class CustomElementClassLookup
            object --+        
                     |        
    ElementClassLookup --+    
                         |    
FallbackElementClassLookup --+
                             |
                            CustomElementClassLookup
- Known Subclasses:
- 
      
CustomElementClassLookup(self, fallback=None)
Element class lookup based on a subclass method.
You can inherit from this class and override the method:
lookup(self, type, doc, namespace, name)
to lookup the element class for a node. Arguments of the method:
* type:      one of 'element', 'comment', 'PI', 'entity'
* doc:       document that the node is in
* namespace: namespace URI of the node (or None for comments/PIs/entities)
* name:      name of the element/entity, None for comments, target for PIs
If you return None from this method, the fallback will be called.
    | a new object with type S, a subtype of T |  | 
    |  | 
        
          | lookup(self,
        type,
        doc,
        namespace,
        name) |  |  | 
  
    | Inherited from FallbackElementClassLookup:__init__,set_fallback Inherited from object:__delattr__,__format__,__getattribute__,__hash__,__reduce__,__reduce_ex__,__repr__,__setattr__,__sizeof__,__str__,__subclasshook__ | 
| 
    Returns: a new object with type S, a subtype of TOverrides:
        object.__new__
     |