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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 find_common_root(elements):
 """ Find root which is common for all `elements`. Args: elements (list):
 List of double-linked HTMLElement objects. Returns: list: Vector of HTMLElement containing path to common root. """

    if not elements:
        raise UserWarning("Can't find common root - no elements suplied.")

    root_path = el_to_path_vector(elements.pop())

    for el in elements:
        el_path = el_to_path_vector(el)

        root_path = common_vector_root(root_path, el_path)

        if not root_path:
            raise UserWarning(
                "Vectors without common root:\n%s" % str(el_path)
            )

    return root_path