def to_timestamp(self, freq=None, how='<STR_LIT:start>', copy=True):
new_values = self._values<EOL>if copy:<EOL><INDENT>new_values = new_values.copy()<EOL><DEDENT>new_index = self.index.to_timestamp(freq=freq, how=how)<EOL>return self._constructor(new_values,<EOL>index=new_index).__finalize__(self)<EOL>
Cast to DatetimeIndex of Timestamps, at *beginning* of period.

Parameters
----------
freq : str, default frequency of PeriodIndex
    Desired frequency.
how : {'s', 'e', 'start', 'end'}
    Convention for converting period to timestamp; start of period
    vs. end.
copy : bool, default True
    Whether or not to return a copy.

Returns
-------
Series with DatetimeIndex