code: private static String trimLeadingWhitespace(String string) {
          if (string.isEmpty()) {
              return string;
          }
  
          int start = 0;
          char c;
  
          for (int i = 0; i < string.length(); i++) {
              c = string.charAt(i);
              if (!Character.isWhitespace(c)) {
                  start = i;
                  break;
              }
          }
  
          if (start == 0) {
              return string;
          }
  
          return string.substring(start);
      }
docs: Returns a string that contains a copy of a specified string
  without leading whitespaces.
  
  @param string the string to trim leading whitespaces
  @return a string with leading whitespaces trimmed