1. @DomName('WebGL2RenderingContext.getTransformFeedbackVarying')
  2. @DocsEditable()
  3. @Experimental()
ActiveInfo getTransformFeedbackVarying(Program program, int index)

Source 

@DomName('WebGL2RenderingContext.getTransformFeedbackVarying')
@DocsEditable()
@Experimental() // untriaged
ActiveInfo getTransformFeedbackVarying(Program program, int index) =>
    _blink.BlinkWebGL2RenderingContext.instance
        .getTransformFeedbackVarying_Callback_2_(this, program, index);