A REST Endpoint waiting for external assist to POST a flatfile with H2O nodes.
Once successfully submitted, this endpoint will no longer accept any new calls.
It is the caller's responsibility to submit a valid flatfile.
There is no parsing or validation done on the flatfile, except for basic emptiness checks.
The logic for IPv4/IPv6 parsing is hidden in NetworkInit class and is therefore hidden
from this class. As this module is intended to insertable onto classpath of any H2O, it does not rely on
specific NetworkInit implementation.