pub fn failingFileReadPositional(userdata: ?*anyopaque, file: File, data: []const []u8, offset: u64) File.ReadPositionalError!usize
pub fn failingFileReadPositional(userdata: ?*anyopaque, file: File, data: []const []u8, offset: u64) File.ReadPositionalError!usize { _ = userdata; _ = file; _ = offset; for (data) |item| { if (item.len > 0) return error.InputOutput; } return 0; }