@SuppressWarnings("unchecked")
    public <T> List<T> executeWithKeys(Path<T> path) {
        return executeWithKeys((Class<T>) path.getType(), path);
    }
Execute the clause and return the generated key with the type of the given path.
If no rows were created, or the referenced column is not a generated key, null is returned.
Otherwise, the key of the first row is returned.

@param <T>
@param path path for key
@return generated keys
querydsl-sql/src/main/java/com/querydsl/sql/dml/SQLMergeClause.java