code: public XcapResponse putIfMatch(URI uri, String eTag, String mimetype,
  			String content, Header[] additionalRequestHeaders,
  			Credentials credentials) throws IOException {
  
  		if (log.isDebugEnabled()) {
  			log.debug("putIfMatch(uri=" + uri + ", eTag=" + eTag
  					+ ", mimetype=" + mimetype + ", content=" + content
  					+ " , additionalRequestHeaders = ( "
  					+ Arrays.toString(additionalRequestHeaders) + " ) )");
  		}
  
  		final HttpPut request = new HttpPut(uri);
  		setRequestEntity(request, content, mimetype);
  		request.setHeader(XcapConstant.HEADER_IF_MATCH, eTag);
  		return execute(request, additionalRequestHeaders, credentials);
  
  	}
docs: /*
  (non-Javadoc)
  
  @see XcapClient#putIfMatch(java.net.URI,
  java.lang.String, java.lang.String, java.lang.String,
  Header[],
  Credentials)