code: public static CommandLine forAssist(String rawCommandLine) {
          final List<String> splitCommandLine = splitCommandLine(rawCommandLine);
  
          // If the commandLine ends with a space (or is empty), we manually insert an empty arg.
          // This implies that the user wanted assistance about the NEXT argument and not the last one that was typed.
          if (rawCommandLine.isEmpty() || rawCommandLine.endsWith(" ")) {
              splitCommandLine.add("");
          }
  
          return new CommandLine(splitCommandLine);
      }
docs: Parse the command line for an assist operation.
  Differs from {@link #forExecute(String)} in that if the command line was empty or ended with a space, a single
  empty element will be added to it.
  Essentially, the command line will never return empty from this operation.
  
  @param rawCommandLine Command line to parse.
  @return Parsed command line for assistance.