code: public static <P> List<P> extractPayloads(final List<? extends Record<P>> records) {
          List<P> payloads = new ArrayList<>();
          for (Record<P> record : records) {
              payloads.add(record.getPayload());
          }
          return payloads;
      }
docs: Extract the payload form each record.
  
  @param records the list of records
  @param <P>     the type of payload
  @return the list of payloads