+------------+-------------------------+------------------------+
| Field Size |        Description      |       Data Type        |
+------------+-------------------------+------------------------+
| 0+         | witness_component count | var_int                |
| ?          | witness_components      | witness_component[]    |
+------------+-------------------------+------------------------+

+------------+------------------+-----------+
| Field Size |   Description    | Data Type |
+------------+------------------+-----------+
| 0+         | component length | var_int   |
| ?          | component        | uchar[]   |
+------------+------------------+-----------+