code: function validate_op_args(raw_arg0, op, op_params) {
          const arg0 = undefined === raw_arg0
              ? ALL_ITEMS
              : raw_arg0
              ; // eslint-disable-line indent
          switch (true) {
              case ALL_ITEMS === arg0:
              case arg0 instanceof Query:
              case 'string' === typeof arg0:
              case 'number' === typeof arg0:
                  if (op && 'string' !== typeof op) {
                      throw new Error([
                          'When calling a bullpen operation,',
                          'if arg 1 is provided, it must be',
                          'the name of the operation to perform',
                          ].join(' ')); // eslint-disable-line indent
                  } else if (op_params && 'object' !== typeof op_params) {
                      throw new Error([
                          'When calling a bullpen operation,',
                          'if arg 2 is provided, it must be a params object',
                          ].join(' ')); // eslint-disable-line indent
                  }
                  return [ arg0, op, op_params ];
          }
          throw new Error([
              'When calling a bullpen operation, if args are provided,',
              'arg 0 of must be one of:',
              'a string, a number, COLLECTION.ALL_ITEMS, or',
              'an instance of COLLECTION.Query',
              ].join(' ')); // eslint-disable-line indent
      }
docs: eslint-disable-line indent -----------