code: int handleNumbers(String line, BitSet numberBitSet, int startingPoint) {
      int end = startingPoint + 1;
      while (end < line.length() && Character.isDigit(line.charAt(end))) {
        end++;
      }
      if (end == line.length()) {
        if (Character.isDigit(line.charAt(line.length() - 1))) {
          numberBitSet.set(startingPoint, end);
        }
      } else if (Character.isWhitespace(line.charAt(end))
          || line.charAt(end) == ';'
          || line.charAt(end) == ','
          || line.charAt(end) == '='
          || line.charAt(end) == '<'
          || line.charAt(end) == '>'
          || line.charAt(end) == '-'
          || line.charAt(end) == '+'
          || line.charAt(end) == '/'
          || line.charAt(end) == ')'
          || line.charAt(end) == '%'
          || line.charAt(end) == '*'
          || line.charAt(end) == '!'
          || line.charAt(end) == '^'
          || line.charAt(end) == '|'
          || line.charAt(end) == '&'
          || line.charAt(end) == ']') {
        numberBitSet.set(startingPoint, end);
      }
      startingPoint = end - 1;
      return startingPoint;
    }
docs: Marks numbers position based on input.
  
  <p>Assumes that a number starts at the specified position,
  i.e. {@code Character.isDigit(line.charAt(startingPoint)) == true}
  
  @param line           Line where to handle number string
  @param numberBitSet   BitSet to use for position of number
  @param startingPoint  Start point
  
  @return position where number finished