Function mln_map_create_with_loader 

pub unsafe extern "C" fn mln_map_create_with_loader(
    frontend: *mut MLNHeadlessFrontend,
    pixel_ratio: c_float,
    mode: MLNMapMode,
    request_callback: MLNResourceCallback,
    user_data: *mut c_void,
) -> *mut MLNMap

Create a new map instance with custom resource loader.