1. @DomName('WebGL2RenderingContext.sampleCoverage')
  2. @DocsEditable()
  3. @Experimental()
void sampleCoverage(num value, bool invert)

Source 

@DomName('WebGL2RenderingContext.sampleCoverage')
@DocsEditable()
@Experimental() // untriaged
void sampleCoverage(num value, bool invert) =>
    _blink.BlinkWebGL2RenderingContext.instance
        .sampleCoverage_Callback_2_(this, value, invert);