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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 to_string(self, buf=None, na_rep='NaN', float_format=None, header=True, index=True, length=False, dtype=False, name=False, max_rows=None):
 """ Render a string representation of the Series. Parameters buf : StringIO-like, optional Buffer to write to. na_rep : str, optional String representation of NaN to use, default 'NaN'. float_format : one-parameter function, optional Formatter function to apply to columns' elements if they are floats, default None. header : bool, default True Add the Series header (index name). index : bool, optional Add index (row) labels, default True. length : bool, default False Add the Series length. dtype : bool, default False Add the Series dtype. name : bool, default False Add the Series name if not None. max_rows : int, optional Maximum number of rows to show before truncating. If None, show all. Returns ------- str or None String representation of Series if ``buf=None``, otherwise None. """


        formatter = fmt.SeriesFormatter(self, name=name, length=length,
                                        header=header, index=index,
                                        dtype=dtype, na_rep=na_rep,
                                        float_format=float_format,
                                        max_rows=max_rows)
        result = formatter.to_string()

        # catch contract violations
        if not isinstance(result, str):
            raise AssertionError("result must be of type unicode, type"
                                 " of result is {0!r}"
                                 "".format(result.__class__.__name__))

        if buf is None:
            return result
        else:
            try:
                buf.write(result)
            except AttributeError:
                with open(buf, 'w') as f:
                    f.write(result)