presto-main/src/main/java/io/prestosql/sql/analyzer/StatementAnalyzer.java/StatementAnalyzer/descriptorToFields
class StatementAnalyzer:        private List<Expression> descriptorToFields(Scope scope)
        {
            ImmutableList.Builder<Expression> builder = ImmutableList.builder();
            for (int fieldIndex = 0; fieldIndex < scope.getRelationType().getAllFieldCount(); fieldIndex++) {
                FieldReference expression = new FieldReference(fieldIndex);
                builder.add(expression);
                analyzeExpression(expression, scope);
            }
            return builder.build();
        }