Instantiate a new write concern given the options.

@api private

@example Instantiate a new write concern mode.

  Mongo::WriteConcern::Acknowledged.new(:w => 1)

@param [ Hash ] options The options to instantiate with.

@option options :w [ Integer, String ] The number of servers or the

  custom mode to acknowledge.

@option options :j [ true, false ] Whether to acknowledge a write to

  the journal.

@option options :fsync [ true, false ] Should the write be synced to

  disc.

@option options :wtimeout [ Integer ] The number of milliseconds to

  wait for acknowledgement before raising an error.

@since 2.0.0

Is this write concern acknowledged.

@example Whether this write concern object is acknowledged.

  write_concern.acknowledged?

@return [ true, false ] Whether this write concern is acknowledged.

@since 2.5.0