public void addPrincipal(ResolvedKerberosPrincipal principal) {
    if (!principals.contains(principal)) {
      principal.setResolvedKerberosKeytab(this);
      principals.add(principal);
    }
  }
Add principal to keytab.

@param principal resolved principal to add
ambari-server/src/main/java/org/apache/ambari/server/serveraction/kerberos/stageutils/ResolvedKerberosKeytab.java