Function SCIPcallExprGetSymData 

pub unsafe extern "C" fn SCIPcallExprGetSymData(
    scip: *mut SCIP,
    expr: *mut SCIP_EXPR,
    symdata: *mut *mut SYM_EXPRDATA,
) -> SCIP_RETCODE

calls the symmetry information callback for an expression

Returns NULL pointer if not implemented.