code: private List<String> getConcepts(Concept c) {
          List<String> keywords = new ArrayList<>();
  
          while (c != null) {
              if (c.synset != null) {
                  keywords.addAll(c.synset);
              }
  
              if (c.children != null) {
                  for (Concept child : c.children) {
                      keywords.addAll(getConcepts(child));
                  }
              }
          }
  
          return keywords;
      }
docs: Returns all named concepts from this taxonomy