If we know about an existing ServiceGroupEntry EPR for
this managed registration, it
will be stored here so that we can attempt to extend
its lifetime rather than adding a new entry.
probably need to make this constructor take content as a
parameter? or make the code that calls constructor then later on call
set on the appropriate resource property.
if we have decided that the remote entry has no resource
lifetime management operations/RPs, then we will set this
to false so that we will not try them again.
Creates an instance of the client library backed by an instance of
a BaseClient derived command line class, inheriting its command line
parameters and redirecting output to the console accordingly.