presto-main/src/main/java/io/prestosql/operator/project/PageFieldsToInputParametersRewriter.java/PageFieldsToInputParametersRewriter/visitInputReference
class PageFieldsToInputParametersRewriter:        @Override
        public RowExpression visitInputReference(InputReferenceExpression reference, Void context)
        {
            int parameter = getParameterForField(reference);
            return field(parameter, reference.getType());
        }