sub SourcePackage { my($funcname, $package) = @_;

$package = caller() if !$package;
return if ! $package->can($funcname);

my $coderef;
{ no strict 'refs'; $coderef = \&{"$package\:\:$funcname"}; }
return B::svref_2object($coderef)->GV->STASH->NAME;
} # SourcePackage()