code: public MobicentsSipSession findDerivedSipSession(String toTag) {
  		dumpDerivedSipSessions();
  		if(derivedSipSessions != null) {
  			return derivedSipSessions.get(toTag);
  		}
  		return null;
  	}
docs: /*
  (non-Javadoc)
  @see org.mobicents.servlet.sip.core.session.MobicentsSipSession#findDerivedSipSession(java.lang.String)