code: public boolean hasCommand(ProtocolKeyword commandName) {
  
          if (commandName instanceof CommandType) {
              return availableCommands.contains(commandName);
          }
  
          return commands.containsKey(commandName.name().toLowerCase());
      }
docs: Check whether Redis supports a particular command given a {@link ProtocolKeyword}. Querying commands using
  {@link CommandType} yields a better performance than other subtypes of {@link ProtocolKeyword}.
  
  @param commandName the command name, must not be {@literal null}.
  @return {@literal true} if the command is supported/available.