Creates a parent expectation that the child expectation will happen a
certain number of times. Unlike
expectN, the child expectation
can be arbitrarily complex and span multiple actions. Also unlike
expectN, each new execution will restart response sequences for
rules with more than one response.
Different occurrences of the child can be interleaved. If ambiguity
checking is disabled, progressing on an existing occurrence is
preferred over starting a new occurrence when it's ambiguous.