# File lib/edi4r/diagrams.rb, line 103
    def Diagram.create( std, params )
      case std
      when 'E' # UN/EDIFACT
        par = {:d0051 => 'UN', 
          #           :d0057 => '',
          :is_iedi => false }.update( params )
      when 'I' # SAP IDocs
        par = params
        #      raise "Not implemented yet!"
      else
        raise "Unsupported syntax standard: #{std}"
      end

      if Diagram.caching?
        #
        # Use param set as key for caching
        #
        key = par.sort {|a,b| a.to_s <=> b.to_s}.hash
        obj = @@cache[key]
        return obj unless obj.nil?
        
        obj = new( std, par )
        @@cache[key] = obj # cache & return it

      else
        new( std, par )
      end
    end