code: private Chunk setAttribute(String name, Object obj) {
  		if (attributes == null)
  			attributes = new HashMap();
  		attributes.put(name, obj);
  		return this;
  	}
docs: Sets an arbitrary attribute.
  
  @param name
  the key for the attribute
  @param obj
  the value of the attribute
  @return this <CODE>Chunk</CODE>