code: private static String[] parseMultipleHeaderValues(final String headerValue) {
  	
  		if (headerValue == null)
  			return new String[0];
  	
  		String trimmedHeaderValue = headerValue.trim();
  		
  		if (trimmedHeaderValue.isEmpty())
  			return new String[0];
  	
  		return trimmedHeaderValue.split("\\s*,\\s*|\\s+");
  	}
docs: Parses a header value consisting of zero or more space / comma /
  space+comma separated strings. The input string is trimmed before
  splitting.
  
  @param headerValue The header value, may be {@code null}.
  
  @return A string array of the parsed string items, empty if none
  were found or the input was {@code null}.