Concatenating LazyStrings

If I've got a pretty printer (for instance, for llvm's Twine type (
https://github.com/llvm/llvm-project/blob/6d03227c16ee1950db0e1aa05fbc3201770248eb/llvm/utils/gdb-scripts/prettyprinters.py#L354
+ https://llvm.org/doxygen/classllvm_1_1Twine.html ) that wants to pretty
print a string made up of other strings (from other pretty printers) - how
would I do that?

Specifically, I can't figure out how to correctly concatenate a gdb
LazyString value with another string. (even if I have to stringify the
LazyString (making it unlazy) in the process - calling ".value()" on the
LazyString doesn't seem to be enough - I can't seem to figure out how to
to-string-ify that resulting gdb Value (it doesn't have a pretty printer
that I can find - nor a to_string/str/string() function) to then
concatenate it with another string)