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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 export(outfile, pk):
 """Export a MultiplyParameters node, identified by PK, to plain text"""

    load_dbenv_if_not_loaded(
    )  # Important to load the dbenv in the last moment

    from aiida.orm import load_node
    node = load_node(pk)
    string = str(node)

    if outfile:
        with open(outfile, 'w') as f:
            f.write(string)
    else:
        click.echo(string)