code: private static SyntaxType register(String id, String name)
      {
          SyntaxType syntaxType = new SyntaxType(id, name);
          KNOWN_SYNTAX_TYPES.put(id, syntaxType);
          return syntaxType;
      }
docs: Register a Syntax Type.
  
  @param id see {@link SyntaxType#SyntaxType(String, String)}
  @param name see {@link SyntaxType#SyntaxType(String, String)}
  @return the created Syntax Type object