code: def mem_extend(self, start: int, size: int) -> None:
          
          m_extend = self.calculate_extension_size(start, size)
          if m_extend:
              extend_gas = self.calculate_memory_gas(start, size)
              self.min_gas_used += extend_gas
              self.max_gas_used += extend_gas
              self.check_gas()
              self.memory.extend(m_extend)
docs: Extends the memory of this machine state.
  
          :param start: Start of memory extension
          :param size: Size of memory extension