A helper function that takes payload fragments and returns a contiguous chunk of memory

[pavel-kirienko]

          > One missing feature is a trivial helper function that takes payload fragments and returns a contiguous chunk of memory instead (this is expensive both memory-wise and time-wise).

Do we have a ticket for this? I think almost all applications are going to want the contiguous chunk of memory and not the fragments, so we're kind of feature incomplete without this function.

Originally posted by @lydia-at-amazon in #38 (comment)