code: def merge(self, other, inplace=False):
          
          holidays = self.merge_class(self, other)
          if inplace:
              self.rules = holidays
          else:
              return holidays
docs: Merge holiday calendars together.  The caller's class
          rules take precedence.  The merge will be done
          based on each holiday's name.
  
          Parameters
          ----------
          other : holiday calendar
          inplace : bool (default=False)
              If True set rule_table to holidays, else return array of Holidays