code: public static Collection<String> getPropertyNames(Channel channel) {
  		Collection<String> propertyNames = new HashSet<String>();
  		for (Property property : channel.getProperties()) {
  			if (property.getValue() != null)
  				propertyNames.add(property.getName());
  		}
  		return propertyNames;
  	}
docs: Return a list of property names associated with this channel
  
  @param channel - channel to be processed
  @return Collection of names of properties