parameters: (self, dt)
return_statement: return dt
docstring: Roll provided date backward to next offset only if not on offset.
docstring_summary: Roll provided date backward to next offset only if not on offset.
docstring_tokens: Roll provided date backward to next offset only if not on offset .
function: def rollback(self, dt):
          """
          Roll provided date backward to next offset only if not on offset.
          """
          if not self.is_on_offset(dt):
              if self.n >= 0:
                  dt = self._prev_opening_time(dt)
              else:
                  dt = self._next_opening_time(dt)
              return self._get_closing_time(dt)
          return dt
function_tokens: def rollback ( self , dt ) : if not self . is_on_offset ( dt ) : if self . n >= 0 : dt = self . _prev_opening_time ( dt ) else : dt = self . _next_opening_time ( dt ) return self . _get_closing_time ( dt ) return dt