Create RelNode of a select query with concat

Question

I went through the documentation of Apache Calcite. Is the relNode correct for the following query in BigQuery?

SELECT CONCAT('a or b',' ', '\n', first_name) 
FROM foo.schema.employee
WHERE first_name = 'name';

relNode = builder
          .scan("schema.employee")
          .filter(builder.call(SqlStdOperatorTable.EQUALS,
                         builder.field("first_name"), 
                         builder.literal("name"))
          .project(builder.call(SqlStdOperatorTable.CONCAT,
                           builder.literal("a or b"),
                           builder.literal(" "),
                           builder.literal("\\n"),
                           builder.field(first_name)))
          .build()  

Answer 1

That looks correct at a glance. I would suggest you confirm by looking at the query results and also by converting your RelNode to SQL.