code: def search_db(self, search):
          
  
          def search_callback(_, address, balance):
              """
  
              :param _:
              :param address: The address of the contract with the code in search
              :param balance: The balance of the corresponding contract
              """
              print("Address: " + address + ", balance: " + str(balance))
  
          try:
              self.leveldb.search(search, search_callback)
  
          except SyntaxError:
              raise CriticalError("Syntax error in search expression.")
docs: Searches the corresponding code
          :param search: The code part to be searched