@type bool $header_text Whether to display custom header text. Default false.
@type int $width Width in pixels of the custom header image. Default 1260.
@type int $height Height in pixels of the custom header image. Default 240.
@type bool $flex_height Whether to allow flexible-height header images. Default true.
@type string $admin_head_callback Callback function used to style the image displayed in
the Appearance > Header screen.
@type string $admin_preview_callback Callback function used to create the custom header markup in
the Appearance > Header screen.
}

Required: 否

Default: —