SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Function quantiles (children 2)
     ExpressionList (children 1)
      Function CAST (children 1)
       ExpressionList (children 2)
        Function now (children 1)
         ExpressionList
        Literal \'DateTime(\\\'UTC\\\')\'
     ExpressionList (children 1)
      Literal Float64_0.5
   Literal UInt64_0
