<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def font(self):
 """Font object controlling text format defaults for this chart."""

        defRPr = (
            self._chartSpace
                .get_or_add_txPr()
                .p_lst[0]
                .get_or_add_pPr()
                .get_or_add_defRPr()
        )
        return Font(defRPr)