The TDictionary<K,V> is not subtype of TEnumerable<...>?

[hl4]

I simplified my code as follow, I was expecting to create a dictionary from another, but it fails.
actual := TCounter.Create(expected); raise a compiling error.

dictionarytest.pas(12,37) Error: Incompatible type for arg no. 1: Got "TDictionary<System.Char,System.LongInt>", expected "TEnumerable<dictionarytest.TPair<System.Char,System.LongInt>>"

I dug some source code, but it is too complex to find the inheritance of TDictionary class.
Please help, if I took something wrong.

{$mode objfpc}{$H-}{$J+}
program dictionarytest;

uses Generics.Collections;
type
  TCounter = specialize TDictionary<Char, Integer>;

var
  expected, actual: TCounter; 
begin
  expected := TCounter.Create;
  actual := TCounter.Create(expected);
end.
```