code: def last_instr(self, start, end, instr, target=None, exact=True):
          
  
          code = self.code
          # Make sure requested positions do not go out of
          # code bounds
          if not (start >= 0 and end <= len(code)):
              return None
  
          try:
              None in instr
          except:
              instr = [instr]
  
          result_offset = None
          current_distance = self.insts[-1].offset - self.insts[0].offset
          extended_arg = 0
          # FIXME: use self.insts rather than code[]
          for offset in self.op_range(start, end):
              op = code[offset]
  
              if op == self.opc.EXTENDED_ARG:
                  arg = code2num(code, offset+1) | extended_arg
                  extended_arg = extended_arg_val(self.opc, arg)
                  continue
  
              if op in instr:
                  if target is None:
                      result_offset = offset
                  else:
                      dest = self.get_target(offset, extended_arg)
                      if dest == target:
                          current_distance = 0
                          result_offset = offset
                      elif not exact:
                          new_distance = abs(target - dest)
                          if new_distance <= current_distance:
                              current_distance = new_distance
                              result_offset = offset
                              pass
                          pass
                      pass
                  pass
              extended_arg = 0
              pass
          return result_offset
docs: Find the last <instr> in the block from start to end.
          <instr> is any python bytecode instruction or a list of opcodes
          If <instr> is an opcode with a target (like a jump), a target
          destination can be specified which must match precisely if exact
          is True, or if exact is False, the instruction which has a target
          closest to <target> will be returned.
  
          Return index to it or None if not found.