code: def remove(self, link_type, product, linked_product, identifierType=None):
          
          return bool(self.call('catalog_product_link.remove',
                  [link_type, product, linked_product, identifierType]))
docs: Remove a product link
  
          :param link_type: type of link, one of 'cross_sell', 'up_sell',
                  'related' or 'grouped'
          :param product: ID or SKU of product
          :param linked_product: ID or SKU of linked product to unlink
          :param identifierType: Defines whether the product or SKU value is
                                 passed in the "product" parameter.
  
          :return: boolean