code: @Override
  	public EcodDomain getDomainsById(String ecodId) throws IOException {
  		if(ecodId == null || ecodId.isEmpty()) {
  			return null;
  		}
  
  		Matcher match = ECOD_RE.matcher(ecodId);
  		String pdbId = null;
  		if( match.matches() )
  			pdbId = match.group(1);
  		List<EcodDomain> doms = getDomainsForPdb(pdbId);
  		if(doms == null) {
  			logger.debug("Null domains for {} from {}",pdbId,ecodId);
  			return null;
  		}
  		logger.debug("Got {} domains from {}",doms.size(),pdbId);
  		for(EcodDomain d: doms) {
  			if(ecodId.equals(d.getDomainId())) {
  				return d;
  			}
  		}
  		return null;
  	}
docs: Get a particular ECOD domain by the domain ID (e.g. "e4hhbA1")
  @param ecodId
  @return
  @throws IOException