SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function quantiles (children 2)
     ExpressionList (children 1)
      Function CAST (children 1)
       ExpressionList (children 2)
        Literal NULL
        Literal \'Nullable(UInt32)\'
     ExpressionList (children 2)
      Literal Float64_0.1
      Literal Float64_0.2
