code: function setWhitespace($ws) {
  		if (is_array($ws)) {
  			$this->whitespace = array_fill_keys(array_values($ws), true);
  			$this->buildCharMap();
  		} else {
  			$this->setWhiteSpace(str_split($ws));
  		}
  	}
docs: Sets characters to be recognized as whitespace
  
  Used like: setWhitespace('ab') or setWhitespace(array('a' => true, 'b', 'c'));
  @param string|array $ws
  @see getWhitespace();