public static Collection<ContentStream> toContentStreams(final String str,final String contentType){
  if (str == null)   return null;
  ArrayList<ContentStream> streams=new ArrayList<>(1);
  ContentStreamBase ccc=new ContentStreamBase.StringStream(str);
  ccc.setContentType(contentType);
  streams.add(ccc);
  return streams;
}

public static Collection < ContentStream > toContentStreams ( final String str , final String contentType ) { if ( str == null ) return null ; ArrayList < ContentStream > streams = new ArrayList < > ( 1 ) ; ContentStreamBase ccc = new ContentStreamBase . StringStream ( str ) ; ccc . setContentType ( contentType ) ; streams . add ( ccc ) ; return streams ; }
take a string and make it an iterable contentstream
