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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 _traverse_tree(tree, path):
 """Traverses the permission tree, returning the permission at given permission path."""

        path_steps = (step for step in path.split('.') if step != '')
        # Special handling for first step, because the first step isn't under 'objects'
        first_step = path_steps.next()
        subtree = tree[first_step]

        for step in path_steps:
            subtree = subtree['children'][step]
        return subtree