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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 get_tree_depth( self ):
        ''' Finds depth of this tree. '''
        if (self.children):
            depth = 1
            childDepths = []
            for child in self.children:
                childDepths.append( child.get_tree_depth() )
            return depth + max(childDepths)
        else:
            return 0