docs: protected byte[] readByteArray(ObjectInput input) throws IOException {
          int len = input.readInt();
          if (-1 == len) {
              if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled()) {
                  Tr.debug(tc, "read byte[] found -1 length marker");
              }
              return null;
          }
          byte[] value = new byte[len];
          input.readFully(value);
          return value;
      }