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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 serialize(ms, version=_default_version, properties=True, pretty_print=False, color=False):
 """Serialize an MRS structure into a SimpleMRS string."""

    delim = '\n' if pretty_print else _default_mrs_delim
    output = delim.join(
        _serialize_mrs(m, properties=properties,
                       version=version, pretty_print=pretty_print)
        for m in ms
    )
    if color:
        output = highlight(output)
    return output