code: public boolean isSecurityDomain(String securityDomainName) throws Exception {
          Address addr = Address.root().add(SUBSYSTEM, SUBSYSTEM_SECURITY);
          String haystack = SECURITY_DOMAIN;
          return null != findNodeInList(addr, haystack, securityDomainName);
      }
docs: Checks to see if there is already a security domain with the given name.
  
  @param securityDomainName the name to check
  @return true if there is a security domain with the given name already in existence
  @throws Exception any error