def _getEntry(root):
    """
    Get the node in the xml data that contains the result from the query to save. If multiple entries are found
    in the query result, this function raises an error.
    
    :param root: Root of the XML data from the arXiv query
    :raises: ValueError is the entry cannot be extracted from the XML data
    :returns: Node that contains the results from the query
    """
    entry = None
    for i in root:
        if i.tag.endswith('entry'):
            if entry is not None:
                raise ValueError('Multiple entries in result')
            entry = i
    return entry