SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 1)
    Identifier _part
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier mt
   ExpressionList (children 1)
    OrderByElement (children 1)
     Function tupleElement (children 1)
      ExpressionList (children 2)
       Function mergeTreePartInfo (children 1)
        ExpressionList (children 1)
         Identifier _part
       Literal \'max_block\'
