code: private Class getMapType()
    {
      Class mapType = Map.class;
      IParsedElement parent = getParsedElement().getParent();
      if( parent instanceof NewExpression )
      {
        IType newType = ((NewExpression)parent).getType();
        IJavaClassInfo classInfo = IRTypeResolver.getJavaBackedClass(newType);
        Class javaBackedClass = classInfo != null ? classInfo.getBackingClass() : null;
        if( classInfo != null && javaBackedClass != null )
        {
          mapType = javaBackedClass;
        }
        else if( JavaTypes.getJreType(AbstractMap.class).isAssignableFrom( newType ) )
        {
          mapType = AbstractMap.class;
        }
      }
      return mapType;
    }
docs: Try to get a more specific class instead of using the Map interface
  i.e., invokevirtual is significantly faster then invokeinterface.