"admin-preview-callback" in "custom-header" probably used to work

[RSalnikov]

Trying to do any thing with "admin_header_image" i found out, that this callback doesn't work at all. I found, it works when we currently placing at one of several steps.
1) Open created page in Appearance -> Header ​https://github.com/WordPress/WordPress/blob/7004afe4f4bac1fd17a142051832bdf6be8e6fcf/wp-admin/includes/class-custom-image-header.php#L73
2) There is should be some steps but they are absent in the page ​https://github.com/WordPress/WordPress/blob/7004afe4f4bac1fd17a142051832bdf6be8e6fcf/wp-admin/includes/class-custom-image-header.php#L1031

[joyously]

What was it that "doesn't work anymore"? Did it ever work? What are you referring to?
Perhaps your question should be on the support forums instead.

[RSalnikov]

Replying to joyously:

What was it that "doesn't work anymore"? Did it ever work? What are you referring to?
Perhaps your question should be on the support forums instead.

I thought it used to work. My bad if this callback is working correctly. Would be nice if we have more examples how to use this callback, because right now i stuck and don't know where i can digging in to solve my issue...

[RSalnikov]

Ah, i confused some things. Thank for helping=)

[SergeyBiryukov]

Thanks for the follow-up!