code: func (h *Client) ProductCustomDimension(productCustomDimension string) *Client {
  	h.productCustomDimension = productCustomDimension
  	h.productCustomDimensionSet = true
  	return h
  }
docs: // A product-level custom dimension where dimension index is
  // a positive integer between 1 and 200, inclusive. Product
  // index must be a positive integer between 1 and 200, inclusive.
  // For analytics.js the Enhanced Ecommerce plugin must be installed
  // before using this field.