code: public IconProviderBuilder forShape(String shapeName, Icon icon)
  	{
  		setType(Type.MODEL);
  		shapeIcons.put(shapeName, checkNotNull(icon));
  		return this;
  	}
docs: Sets the icon to use for a specific shape/group in a {@link MalisisModel}.
  
  @param shapeName the shape name
  @param icon the icon
  @return the icon provider builder