ExpGots are used to represent what was expected, and what was received. If
nothing was expected, then any output will be valid. If something was expected, then
what was received must match
Transforms the written test cases from whatever data language was used
to conditions that ft understands. Add any language by implementing
the Inputter trait
This module specifies the output format of an ft test case
To add an output format, simply implement the FtOutput trait. This is what
is done by YmlOutput and JsonOutput for example