Javadoc
Gets the application delta also including instances from the passed remote regions, with the instances from the
local region.
The remote regions from where the instances will be chosen can further be restricted if this application does not
appear in the whitelist specified for the region as returned by
EurekaServerConfig#getRemoteRegionAppWhitelist(String) for a region. In case, there is no whitelist
defined for a region, this method will also look for a global whitelist by passing null
to the
method
EurekaServerConfig#getRemoteRegionAppWhitelist(String)