SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Function quantileExactWeighted (children 2)
     ExpressionList (children 2)
      Identifier x
      Identifier y
     ExpressionList (children 1)
      Literal Float64_0.5
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Subquery (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 2)
         SelectQuery (children 1)
          ExpressionList (children 2)
           Function CAST (alias x) (children 1)
            ExpressionList (children 2)
             Literal NULL
             Literal \'Nullable(UInt8)\'
           Function CAST (alias y) (children 1)
            ExpressionList (children 2)
             Literal UInt64_1
             Literal \'Nullable(UInt8)\'
         SelectQuery (children 1)
          ExpressionList (children 2)
           Function CAST (alias x) (children 1)
            ExpressionList (children 2)
             Literal UInt64_2
             Literal \'Nullable(UInt8)\'
           Function CAST (alias y) (children 1)
            ExpressionList (children 2)
             Literal NULL
             Literal \'Nullable(UInt8)\'
