SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 1)
    Function sum (children 1)
     ExpressionList (children 1)
      Function equals (children 1)
       ExpressionList (children 2)
        Identifier l._part_offset
        Identifier r._parent_part_offset
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier test (alias l)
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      Function mergeTreeProjection (alias r) (children 1)
       ExpressionList (children 3)
        Function currentDatabase (children 1)
         ExpressionList
        Identifier test
        Identifier p
     TableJoin (children 1)
      ExpressionList (children 1)
       Identifier a
   Set
