def append_xy( x=[], y=[],name=nil, options={})
         @plugins.each {|plugin| plugin.append_xy(x.clone,y.clone,name, options)}
      end
def append_xy( x=[], y=[],name=nil, options={})
         @plugins.each {|plugin| plugin.append_xy(x.clone,y.clone,name, options)}
      end
Accept either [[x,y],[x,y]]
Hash [name] = y
 array [x,y ]
Interface Functions