docs: public ReadModifyWriteRow append(
        @Nonnull String familyName, @Nonnull ByteString qualifier, @Nonnull ByteString value) {
      Validations.validateFamily(familyName);
      Preconditions.checkNotNull(qualifier, "Qualifier can't be null");
      Preconditions.checkNotNull(value, "Value can't be null");
      Preconditions.checkArgument(!value.isEmpty(), "Value can't be empty");
  
      ReadModifyWriteRule rule =
          ReadModifyWriteRule.newBuilder()
              .setFamilyName(familyName)
              .setColumnQualifier(qualifier)
              .setAppendValue(value)
              .build();
  
      builder.addRules(rule);
  
      return this;
    }