in src/main/java/org/apache/cassandra/distributed/api/QueryResults.java [102:112]
        public Builder row(Object... values)
        {
            if (numColumns == UNSET)
                numColumns = values.length;
            if (numColumns != values.length)
                throw new AssertionError("Attempted to add row with different column count; " +
                                         "expected " + numColumns + " columns but given " + Arrays.toString(values));
            results.add(values);
            return this;
        }