presto-main/src/main/java/io/prestosql/execution/ParameterExtractor.java/ParameterExtractor/getParameters
class ParameterExtractor:    public static List<Parameter> getParameters(Statement statement)
    {
        ParameterExtractingVisitor parameterExtractingVisitor = new ParameterExtractingVisitor();
        parameterExtractingVisitor.process(statement, null);
        return parameterExtractingVisitor.getParameters();
    }