docs: def run(self, realm, users):
  		"""
  		Requests a TGT in the name of the users specified in users. 
  		Returns a list of usernames that are in the domain.
  
  		realm: kerberos realm (domain name of the corp)
  		users: list : list of usernames to test
  		"""
  		existing_users = []
  		for user in users:
  			logging.debug('Probing user %s' % user)
  			req = KerberosUserEnum.construct_tgt_req(realm, user)
  			rep = self.ksoc.sendrecv(req.dump(), throw = False)
  			
  			if rep.name != 'KRB_ERROR':	
  				# user doesnt need preauth, but it exists
  				existing_users.append(user)
  			
  			elif rep.native['error-code'] != KerberosErrorCode.KDC_ERR_PREAUTH_REQUIRED.value:
  				# any other error means user doesnt exist
  				continue
  			
  			else:
  				# preauth needed, only if user exists
  				existing_users.append(user)
  
  		return existing_users