Possible issue with .content given a DOM::Tiny object

[zoffixznet]

Calling .content with another DOM::Tiny object works if you create one using .parse method, but seems to crash due to modification of immutable DOM::Tiny if you create one using the .at method:

2017.10.3 zoffix@VirtualBox~$ perl6 -MDOM::Tiny -e 'with DOM::Tiny.parse: "<foo><bar>meow</bar></foo>" { for .find("foo") { .content: DOM::Tiny.parse: "meow" }; say ~$_ };'
<foo>meow</foo>
2017.10.3 zoffix@VirtualBox~$ perl6 -MDOM::Tiny -e 'with DOM::Tiny.parse: "<foo><bar>meow</bar></foo>" { for .find("foo") { .content: DOM::Tiny.parse("<b>meow</b>").at: "b" }; say ~$_ };'
Cannot modify an immutable DOM::Tiny 
  in sub _link at /home/zoffix/.rakudobrew/moar-master/install/share/perl6/site/sources/C389645DC4FF96E58E0EB64B8ABD2EE318524B63 (DOM::Tiny) line 1156
  in block  at /home/zoffix/.rakudobrew/moar-master/install/share/perl6/site/sources/C389645DC4FF96E58E0EB64B8ABD2EE318524B63 (DOM::Tiny) line 946
  in method content at /home/zoffix/.rakudobrew/moar-master/install/share/perl6/site/sources/C389645DC4FF96E58E0EB64B8ABD2EE318524B63 (DOM::Tiny) line 944
  in block  at -e line 1
  in block <unit> at -e line 1




2017.10.3 zoffix@VirtualBox~$ perl6 -MDOM::Tiny -e 'with DOM::Tiny.parse: "<foo><bar>meow</bar></foo>" { for .find("foo") { .content: ~DOM::Tiny.parse("<b>meow</b>").at: "b" }; say ~$_ };'
<foo><b>meow</b></foo>