PFNGLSHADINGRATEIMAGEPALETTENVPROCDart typedef
        PFNGLSHADINGRATEIMAGEPALETTENVPROCDart =
     void Function(int viewport, int first, int count, Pointer<Uint32>  rates)
    
    
    
Implementation
typedef PFNGLSHADINGRATEIMAGEPALETTENVPROCDart =
    void Function(int viewport, int first, int count, Pointer<Uint32> rates);