SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 2)
    Function coalesce (alias x) (children 1)
     ExpressionList (children 2)
      Function toNullable (children 1)
       ExpressionList (children 1)
        Literal UInt64_1
      Function toNullable (children 1)
       ExpressionList (children 1)
        Literal UInt64_2
    Function toTypeName (children 1)
     ExpressionList (children 1)
      Identifier x