Encode encodes all the vals to the returned byte slice with little-endianness.

Pad returns a slice of n zero bytes.

R creates and returns a new Extras containing a single read using the given range and data.

W creates and returns a new Extras containing a single write using the given range and data.

Cmd is a custom implementation of the api.Cmd interface that simplifies testing compiler generated commands.

Extras is a helper wrapper around an api.CmdExtras has helpers methods for adding read and writ observations.