SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 1)
    Literal UInt64_1
   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
