my ($level,$pkg,$callpkg);
if ($_[1]=~/^[0-9]+$/) {
    # called as method
    $pkg=shift;
    $level=shift;
    (undef)=shift;
    $callpkg=caller($level);
    $pkg->export($callpkg,@_);
} else {
    # called as function
    $level=shift;
    $pkg=shift;
    $callpkg=caller($level);
    heavy_export($pkg,$callpkg,@_);
}