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package Mo::chain;my$M="Mo::";
$VERSION=0.31;
*{$M.'chain::e'}=sub{my($P,$e,$o)=@_;$o->{chain}=sub{my($m,$n,%a)=@_;$a{chain}or return$m;sub{$#_?($m->(@_),return$_[0]):$m->(@_)}}};