code: function doUntab(input, depth = undefined, trim = undefined){
  	
  	/** Not a string? Leave it. */
  	if("[object String]" !== Object.prototype.toString.call(input))
  		return input;
  	
  	if(trim === undefined)  trim  = _trim;
  	if(depth === undefined) depth = _depth;
  	
  	/** Strip leading and trailing lines if told to */
  	if(trim)
  		input = input.replace(/^(?:[\x20\t]*\n)*|(?:\n[\x20\t]*)*$/gi, "");
  	
  	const untabPatt = new RegExp("^(?:" + untabChar + "){0," + depth + "}", "gm");
  	return input.replace(untabPatt, "");
  }
docs: Remove leading indentation using Chai's current untab- settings.
  
  Called automatically, but exposed for external use. If the supplied
  argument isn't a string, it's returned untouched without further ado.
  
  Arguments beyond the first are optional: if either depth or trim are
  omitted, they default to those set for the current suite level.
  
  @param {Mixed} input
  @param {Number} depth
  @param {Boolean} trim
  @return {Mixed|String}
  @public