SelectWithUnionQuery (children 2)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function toNullable (alias x) (children 1)
     ExpressionList (children 1)
      Function toLowCardinality (children 1)
       ExpressionList (children 1)
        Literal UInt64_123456789
 Identifier PrettyCompact
