NativeLsl_push_sample_vtp typedef
        NativeLsl_push_sample_vtp =
     Int32 Function(lsl_outlet out, Pointer<Void>  data, Double timestamp, Int32 pushthrough)
    
    
    
Implementation
typedef NativeLsl_push_sample_vtp =
    ffi.Int32 Function(
      lsl_outlet out,
      ffi.Pointer<ffi.Void> data,
      ffi.Double timestamp,
      ffi.Int32 pushthrough,
    );