type ('args, 'ret) tA mock is something that can be used in place of function.
('args, 'ret) t is similar to 'args -> 'ret except that:
val make : name:string ‑> ('args, 'ret) tBuild an unconfigured mock. Calling an unconfigured mock will raise an exception that contains the name of the mock.
val call : ('args, 'ret) t ‑> 'args ‑> 'retCall the mock:
exception Mock_not_configured of stringcall will raise this exception if the mock has not been configured.
val recorded_calls : ('args, 'ret) t ‑> 'args listReturn the list of arguments this mock has received. The list is in the same order as the calls.