Apache Druid

Specifically, I'm trying to achieve this:
```new TopNQueryBuilder().virtualColumns(new ExpressionVirtualColumn(
                "uniqueRecordIdentifier",
                "concat(\"comumnNameA\",\"columnNameB\")",
                ColumnType.STRING,
                ExprMacroTable.nil()))
        ...
        .build();```

I forgot to mention that I initially tried to locate the `org.hyperic:sigar:1.6.5.132` dependency in `mavenCentral()` repository.

What are you trying to do? If you're just trying to create Druid query objects so you can serialize them, you can ignore sigar (exclude the dependency). It isn't used in those code paths

As to ANTLR, I am not sure if we are tied to that older version in some way. That's an area of the code base I am not too familiar with