code: public Pattern getProcessPattern() {
          String arg = extraArgs.size() > 0 ? extraArgs.get(0) : null;
          try {
              return arg != null && getPid() == null ?
                      Pattern.compile(arg, Pattern.CASE_INSENSITIVE)
                      : null;
          } catch (PatternSyntaxException exp) {
              throw new IllegalArgumentException("Invalid pattern '" + arg + "' for matching process names", exp);
          }
  
      }
docs: A pattern used for matching a process name. If  {@link #getPid()} return a non-null value,
  this method returns always null
  
  @return pattern to match a process name or null