code: function(doNotReassessFlashSupport) {
      var effectiveScriptOrigin, frame, frameError, previousState = _flashState.sandboxed, isSandboxed = null;
      doNotReassessFlashSupport = doNotReassessFlashSupport === true;
      if (_pageIsFramed === false) {
        isSandboxed = false;
      } else {
        try {
          frame = window.frameElement || null;
        } catch (e) {
          frameError = {
            name: e.name,
            message: e.message
          };
        }
        if (frame && frame.nodeType === 1 && frame.nodeName === "IFRAME") {
          try {
            isSandboxed = frame.hasAttribute("sandbox");
          } catch (e) {
            isSandboxed = null;
          }
        } else {
          try {
            effectiveScriptOrigin = document.domain || null;
          } catch (e) {
            effectiveScriptOrigin = null;
          }
          if (effectiveScriptOrigin === null || frameError && frameError.name === "SecurityError" && /(^|[\s\(\[@])sandbox(es|ed|ing|[\s\.,!\)\]@]|$)/.test(frameError.message.toLowerCase())) {
            isSandboxed = true;
          }
        }
      }
      _flashState.sandboxed = isSandboxed;
      if (previousState !== isSandboxed && !doNotReassessFlashSupport) {
        _detectFlashSupport(_ActiveXObject);
      }
      return isSandboxed;
    }
docs: Attempt to detect if ZeroClipboard is executing inside of a sandboxed iframe.
  If it is, Flash Player cannot be used, so ZeroClipboard is dead in the water.
  
  @see {@link http://lists.w3.org/Archives/Public/public-whatwg-archive/2014Dec/0002.html}
  @see {@link https://github.com/zeroclipboard/zeroclipboard/issues/511}
  @see {@link http://zeroclipboard.github.io/test-iframes.html}
  
  @returns `true` (is sandboxed), `false` (is not sandboxed), or `null` (uncertain)
  @private