Function ImPlotAnnotationCollection_Append 

pub unsafe extern "C" fn ImPlotAnnotationCollection_Append(
    self_: *mut ImPlotAnnotationCollection,
    pos: ImVec2_c,
    off: ImVec2_c,
    bg: ImU32,
    fg: ImU32,
    clamp: bool,
    fmt: *const c_char,
    ...
)