docs: public boolean updateAttributes(final Collection<Attribute> attrToSend) {
  		if (!this.sentAttrSpecifications) {
  			log.error("Haven't sent type specifications yet, can't send solutions.");
  			return false;
  		}
  		for (Iterator<Attribute> iter = attrToSend.iterator(); iter.hasNext();) {
  			Attribute soln = iter.next();
  			Integer solutionTypeAlias = this.attributeAliases.get(soln
  					.getAttributeName());
  			if (solutionTypeAlias == null) {
  				log.error(
  						"Cannot send solution: Unregistered attribute type: {}",
  						soln.getAttributeName());
  				iter.remove();
  				continue;
  			}
  			soln.setAttributeNameAlias(solutionTypeAlias.intValue());
  		}
  
  		AttributeUpdateMessage message = new AttributeUpdateMessage();
  
  		message.setCreateId(this.createIds);
  
  		message.setAttributes(attrToSend.toArray(new Attribute[] {}));
  
  		this.session.write(message);
  		log.debug("Sent {} to {}", message, this);
  
  		return true;
  	}