Defines the unique identifier of a router, including any certificate or
As of 0.9.9 this data structure is immutable after the two keys and the certificate
are set; attempts to change them will throw an IllegalStateException.
This router specified that they should not be used as a part of a tunnel,
nor queried for the netDb, and that disclosure of their contact information
should be limited.
This is ONLY if the certificate is a hidden type.
Hidden mode may also be specified with a capability in the RouterInfo.
Not recommended for direct use.
Use of RouterInfo.isHidden() (which calls this) is preferred.