Some HTTP requests keep their data not in their own body part, but in various segments known as multiparts. Multiparts consist of their own HTTP (sub-)header and (sub-)body.
You can access multiparts using Interface IF_HTTP_ENTITY. This Interface is contained in both Interface IF_HTTP_REQUEST and Interface IF_HTTP_RESPONSE.
The methods
ADD_MULTIPART() [Creates a new multipart segment in this entity]
GET_MULTIPART() [Gets the requested multipart segment for this entity]
NUM_MULTIPARTS() [Gets the number of multipart segments for this entity]
in Interface IF_HTTP_ENTITY provide the functionality required in order to navigate in the tree of multipart segments.