def lookup(classname)
      if @relations[classname]
        @relations[classname]
      elsif @relations.ignore?(classname) || classname =~ /\*/
        # Ignore explicitly ignored classes and classnames with
        # wildcards in them.  We could expand the wildcard, but that
        # can result in a very long list of classes, like when
        # somebody requires 'Ext.form.*', so for now we do the
        # simplest thing and ignore it.
        Class.new({:name => classname}, false)
      else
        Logger.warn(:extend, "Class #{classname} not found", @doc[:files][0])
        # Create placeholder class
        Class.new({:name => classname}, false)
      end
    end
def lookup(classname)
      if @relations[classname]
        @relations[classname]
      elsif @relations.ignore?(classname) || classname =~ /\*/
        # Ignore explicitly ignored classes and classnames with
        # wildcards in them.  We could expand the wildcard, but that
        # can result in a very long list of classes, like when
        # somebody requires 'Ext.form.*', so for now we do the
        # simplest thing and ignore it.
        Class.new({:name => classname}, false)
      else
        Logger.warn(:extend, "Class #{classname} not found", @doc[:files][0])
        # Create placeholder class
        Class.new({:name => classname}, false)
      end
    end
Looks up class object by name
 When not found, prints warning message.