# File lib/graphviz/attrs.rb, line 56
    def []=( xKey, xValue )
      unless @attributs.keys.include?( xKey.to_s )
        raise ArgumentError, "#{@name} attribut '#{xKey.to_s}' invalid"
      end
      
      @data[xKey.to_s] = GraphViz::Types.const_get(@attributs[xKey.to_s]).new( xValue )

      if @graphviz.nil? == false
        @graphviz.set_position( @name, xKey.to_s, @data[xKey.to_s] )
      end
    end