code: public static String getCompactName(String headerName) {
  
  		String compactName = null;
  		if (JainSipUtils.HEADER_COMPACT_2_FULL_NAMES_MAPPINGS.containsKey(headerName)) {
  			compactName = JainSipUtils.HEADER_COMPACT_2_FULL_NAMES_MAPPINGS.get(headerName);
  		} else {
  			// This can be null if there is no mapping!!!
  			compactName = JainSipUtils.HEADER_FULL_TO_COMPACT_NAMES_MAPPINGS.get(headerName);
  		}
  		if (logger.isDebugEnabled())
  			logger.debug("Fetching compact header name for [" + headerName
  					+ "] returning [" + compactName + "]");
  
  		return compactName;
  
  	}
docs: This method tries to determine compact header name - if passed value is
  compact form it is returned, otherwise method tries to find compact name -
  if it is found, string rpresenting compact name is returned, otherwise
  null!!!
  
  @param headerName
  @return