public static ProcessingChainMultiSources of(
     ProcessingChainSupplier[] sources, ProcessingChainEntry entry) {
   if (sources == null) {
     sources = new ProcessingChainSupplier[0];
   }
   if (entry == null) {
     entry = ProcessingChainEntry.createUnknown();
   }
   ProcessingChain[] chains =
       Arrays.stream(sources)
           .map(it -> it == null ? ProcessingChain.createUnknown() : it.getProcessingChain())
           .toArray(ProcessingChain[]::new);
   return of(chains, entry);
 }
 public static ProcessingChainMultiSources of(
     ProcessingChain[] sources, ProcessingChainEntry entry) {
   if (sources == null) {
     sources = new ProcessingChain[0];
   }
   for (int i = 0; i < sources.length; i++) {
     if (sources[i] == null) {
       sources[i] = ProcessingChain.createUnknown();
     }
   }
   if (entry == null) {
     entry = ProcessingChainEntry.createUnknown();
   }
   return new ProcessingChainMultiSources(sources, entry);
 }