SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 2)
    Identifier nx
    Identifier ny
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier nested
    TablesInSelectQueryElement (children 1)
     ArrayJoin (children 1)
      ExpressionList (children 2)
       Identifier nest.x (alias nx)
       Identifier nest.y (alias ny)
   Function notEmpty (children 1)
    ExpressionList (children 1)
     Identifier nest.y
