perl-JSON-MaybeXS (Use Cpanel::JSON::XS with a fallback to
 JSON::XS and JSON::PP)

This module first checks to see if either Cpanel::JSON::XS or
JSON::XS is already loaded, in which case it uses that module.
Otherwise it tries to load Cpanel::JSON::XS, then JSON::XS,
then JSON::PP in order, and either uses the first module it
finds or throws an error.

It then exports the encode_json and decode_json functions from
the loaded module, along with a JSON constant that returns the
class name for calling new on.

If you're writing fresh code rather than replacing JSON.pm
usage, you might want to pass options as constructor args
rather than calling mutators, so we provide our own new method
that supports that.
