Function ZL_Compressor_Graph_getSuccessors 

pub unsafe extern "C" fn ZL_Compressor_Graph_getSuccessors(
    compressor: *const ZL_Compressor,
    graphid: ZL_GraphID,
) -> ZL_GraphIDList

@returns The successor of the head node in the graph if @p graphid is a static graph, otherwise returns an empty list. @note The array is valid for the lifetime of the @p compressor.