docs: @Override
      public int complete(String buffer, int cursor, List<CharSequence> candidates)
      {
          // For now only support tab completion at the end of the line.
          if (cursor == buffer.length()) {
              // Check for an initial token match?
              if (cursor <= m_maxCommandPrefixLength) {
                  final String bufferu = buffer.toUpperCase();
                  for (final String command : m_commandPrefixes) {
                      if (command.startsWith(bufferu)) {
                          candidates.add(command);
                      }
                  }
                  if (!candidates.isEmpty()) {
                      return 0;
                  }
              }
          }
          return cursor;
      }