Function libgit2_sys::git_cred_ssh_custom_new

pub unsafe extern "C" fn git_cred_ssh_custom_new(
    out: *mut *mut git_cred, 
    username: *const c_char, 
    publickey: *const c_char, 
    publickey_len: size_t, 
    sign_callback: git_cred_sign_callback, 
    payload: *mut c_void
) -> c_int