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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_node_column(cls, node, column_name):
 """Given a ParsedNode, add some fields that might be missing. Return a reference to the dict that refers to the given column, creating it if it doesn't yet exist. """

        if not hasattr(node, 'columns'):
            node.set('columns', {})

        if column_name in node.columns:
            column = node.columns[column_name]
        else:
            column = {'name': column_name, 'description': ''}
            node.columns[column_name] = column

        return column