docs: func (cb ConditionBuilder) buildChildNodes() ([]exprNode, error) {
  	childNodes := make([]exprNode, 0, len(cb.conditionList)+len(cb.operandList))
  	for _, condition := range cb.conditionList {
  		node, err := condition.buildTree()
  		if err != nil {
  			return []exprNode{}, err
  		}
  		childNodes = append(childNodes, node)
  	}
  	for _, ope := range cb.operandList {
  		operand, err := ope.BuildOperand()
  		if err != nil {
  			return []exprNode{}, err
  		}
  		childNodes = append(childNodes, operand.exprNode)
  	}
  
  	return childNodes, nil
  }