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

Source 

@DomName('WebGLRenderingContext.sampleCoverage')
@DocsEditable()
void sampleCoverage(num value, bool invert) =>
    _blink.BlinkWebGLRenderingContext.instance
        .sampleCoverage_Callback_2_(this, value, invert);