code: protected static String getFullHeaderName(String headerName) {
  
  		String fullName = null;
  		if (JainSipUtils.HEADER_COMPACT_2_FULL_NAMES_MAPPINGS.containsKey(headerName)) {
  			fullName = JainSipUtils.HEADER_COMPACT_2_FULL_NAMES_MAPPINGS.get(headerName);
  		} else {
  			fullName = headerName;
  		}
  		if (logger.isDebugEnabled())
  			logger.debug("Fetching full header name for [" + headerName
  					+ "] returning [" + fullName + "]");
  
  		return fullName;
  	}
docs: This method tries to resolve header name - meaning if it is compact - it
  returns full name, if its not, it returns passed value.
  
  @param headerName
  @return