SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Function materialize (alias test) (children 1)
     ExpressionList (children 1)
      Function CAST (children 1)
       ExpressionList (children 2)
        Literal NULL
        Literal \'Nullable(Float64)\'
   ExpressionList (children 3)
    Identifier test
    Function toTypeName (children 1)
     ExpressionList (children 1)
      Identifier test
    Function IF (children 1)
     ExpressionList (children 3)
      Function equals (children 1)
       ExpressionList (children 2)
        Identifier test
        Literal UInt64_0
      Literal UInt64_1
      Literal UInt64_0