text: #include "duckdb/parser/expression/parameter_expression.hpp"
  #include "duckdb/parser/transformer.hpp"
  
  using namespace duckdb;
  using namespace std;
  
  unique_ptr<ParsedExpression> Transformer::TransformParamRef(PGParamRef *node) {
  	if (!node) {
  		return nullptr;
  	}
  	auto expr = make_unique<ParameterExpression>();
  	if (node->number == 0) {
  		expr->parameter_nr = ParamCount() + 1;
  	} else {
  		expr->parameter_nr = node->number;
  	}
  	SetParamCount(max(ParamCount(), expr->parameter_nr));
  	return move(expr);
  }
  