code: def _collect_uncolored_outputs(unspent_outputs, amount):
          
          total_amount = 0
          result = []
          for output in unspent_outputs:
              if output.output.asset_id is None:
                  result.append(output)
                  total_amount += output.output.value
  
              if total_amount >= amount:
                  return result, total_amount
  
          raise InsufficientFundsError
docs: Returns a list of uncolored outputs for the specified amount.
  
          :param list[SpendableOutput] unspent_outputs: The list of available outputs.
          :param int amount: The amount to collect.
          :return: A list of outputs, and the total amount collected.
          :rtype: (list[SpendableOutput], int)