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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 build_act(cls: Type[_Block], node: ast.stmt, test_func_node: ast.FunctionDef) -> _Block: """ Act block is a single node - either the act node itself, or the node that wraps the act node. """

        add_node_parents(test_func_node)
        # Walk up the parent nodes of the parent node to find test's definition.
        act_block_node = node
        while act_block_node.parent != test_func_node:  # type: ignore
            act_block_node = act_block_node.parent  # type: ignore
        return cls([act_block_node], LineType.act)