docs: public DescribePrincipalIdFormatResult withPrincipals(PrincipalIdFormat... principals) {
          if (this.principals == null) {
              setPrincipals(new com.amazonaws.internal.SdkInternalList<PrincipalIdFormat>(principals.length));
          }
          for (PrincipalIdFormat ele : principals) {
              this.principals.add(ele);
          }
          return this;
      }