code: public Attribute getAttribute(final String attributeName) {
  		final Attribute a = attributes.get(attributeName);
  		if (a == null)
  			throw new IllegalArgumentException("Attribute " + attributeName + " doesn't exists");
  		return a;
  	}
docs: Returns the attribute with the given name. Throws an IllegalArgumentException if there is no such attribute.
  
  @param attributeName a {@link java.lang.String} object.
  @return the attribute with the given name