func: constructor(address _base_token, address _traded_token,uint _base_token_seed_amount, uint _traded_token_seed_amount, uint _commission_ratio) public {
        
      admin = tx.origin;  
        
      base_token = _base_token;
      
      traded_token = _traded_token;
      
      base_token_seed_amount = _base_token_seed_amount;
      
      traded_token_seed_amount = _traded_token_seed_amount;
  
      commission_ratio = _commission_ratio;
      
    }