Example 1: provide a default value for all missing branches
+-----+-------------+-------------+
| Row | x           | y           | 
+-----+-------------+-------------+
| 0   | 1           | 2           | 
+-----+-------------+-------------+
| 1   | 2           | 4           | 
+-----+-------------+-------------+
| 2   | 3           | 6           | 
+-----+-------------+-------------+
| 3   | 4           | 8           | 
+-----+-------------+-------------+
| 4   | 5           | 10          | 
+-----+-------------+-------------+
| 5   | -2147483648 | 3           | 
+-----+-------------+-------------+
| 6   | -2147483648 | 6           | 
+-----+-------------+-------------+
| 7   | -2147483648 | 9           | 
+-----+-------------+-------------+
| 8   | -2147483648 | 12          | 
+-----+-------------+-------------+
| 9   | -2147483648 | 15          | 
+-----+-------------+-------------+
| 10  | 4           | -2147483648 | 
+-----+-------------+-------------+
| 11  | 8           | -2147483648 | 
+-----+-------------+-------------+
| 12  | 12          | -2147483648 | 
+-----+-------------+-------------+
| 13  | 16          | -2147483648 | 
+-----+-------------+-------------+
| 14  | 20          | -2147483648 | 
+-----+-------------+-------------+
Example 2: provide a default value for branch y, but skip events where branch x is missing
+-----+----+-------------+
| Row | x  | y           | 
+-----+----+-------------+
| 0   | 1  | 2           | 
+-----+----+-------------+
| 1   | 2  | 4           | 
+-----+----+-------------+
| 2   | 3  | 6           | 
+-----+----+-------------+
| 3   | 4  | 8           | 
+-----+----+-------------+
| 4   | 5  | 10          | 
+-----+----+-------------+
| 10  | 4  | -2147483648 | 
+-----+----+-------------+
| 11  | 8  | -2147483648 | 
+-----+----+-------------+
| 12  | 12 | -2147483648 | 
+-----+----+-------------+
| 13  | 16 | -2147483648 | 
+-----+----+-------------+
| 14  | 20 | -2147483648 | 
+-----+----+-------------+
Example 3: only keep events where branch y is missing and display values for branch x
+-----+----+
| Row | x  | 
+-----+----+
| 10  | 4  | 
+-----+----+
| 11  | 8  | 
+-----+----+
| 12  | 12 | 
+-----+----+
| 13  | 16 | 
+-----+----+
| 14  | 20 | 
+-----+----+