This is used to know how much data a certain header extension will need for
both allocating the resulting data, and deciding how much payload data can
be generated.
Implementations should return as accurate a value as is possible using the
information given in the input buffer.
This is used to know how much data a certain header extension will need for both allocating the resulting data, and deciding how much payload data can be generated.
Implementations should return as accurate a value as is possible using the information given in the input buffer.