Quoting columns in primary key clause of CREATE TABLE statement does not work

A ParseException is thrown when quoting the columns in the primary key clause of a CREATE TABLE statement. The following statement is parsed perfectly:
``CREATE TABLE `FOO` (`ID` INT64, `NAME` STRING(100)) PRIMARY KEY (ID)``

While this statement throws a ParseException:
``CREATE TABLE `FOO` (`ID` INT64, `NAME` STRING(100)) PRIMARY KEY (`ID`)``
