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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def registerJavaUDAF(self, name, javaClassName):
 """Register a Java user-defined aggregate function as a SQL function. :param name: name of the user-defined aggregate function :param javaClassName: fully qualified name of java class [Row(name=u'b', avg=102.0), Row(name=u'a', avg=102.0)] """


        self.sparkSession._jsparkSession.udf().registerJavaUDAF(name, javaClassName)