error[E0599]: the function or associated item `max_encoded_len` exists for struct `Generic<NotMel>`, but its trait bounds were not satisfied
  --> tests/max_encoded_len_ui/not_mel.rs:12:29
   |
4  | struct NotMel;
   | ------------- doesn't satisfy `NotMel: MaxEncodedLen`
...
7  | struct Generic<T> {
   | ----------------- function or associated item `max_encoded_len` not found for this struct because it doesn't satisfy `Generic<NotMel>: MaxEncodedLen`
...
12 |     let _ = Generic::<NotMel>::max_encoded_len();
   |                                ^^^^^^^^^^^^^^^ function or associated item cannot be called on `Generic<NotMel>` due to unsatisfied trait bounds
   |
   = note: trait bound `NotMel: MaxEncodedLen` was not satisfied
note: the trait `MaxEncodedLen` must be implemented
  --> src/max_encoded_len.rs
   |
   | pub trait MaxEncodedLen: Encode {
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   = help: items from traits can only be used if the trait is implemented and in scope
   = note: the following trait defines an item `max_encoded_len`, perhaps you need to implement it:
           candidate #1: `MaxEncodedLen`