code: func (c *DOM) GetFlattenedDocument(depth int, pierce bool) ([]*DOMNode, error) {
  	var v DOMGetFlattenedDocumentParams
  	v.Depth = depth
  	v.Pierce = pierce
  	return c.GetFlattenedDocumentWithParams(&v)
  }
docs: // GetFlattenedDocument - Returns the root DOM node (and optionally the subtree) to the caller.
  // depth - The maximum depth at which children should be retrieved, defaults to 1. Use -1 for the entire subtree or provide an integer larger than 0.
  // pierce - Whether or not iframes and shadow roots should be traversed when returning the subtree (default is false).
  // Returns -  nodes - Resulting node.