title: jMeter multipart request with file upload
body: <p>I have a multipart request that I construct. Each part of the request is a jsonString body and it has a set of headers for the whole request and some for individual multiaprts.</p>
  
  <p>I can use jMeter's 'Send parameters with request' to add Name-value for the jsonStrings, but I cannot specify headers within each of these parts.
  I can specify a header manager for the entire request, but can it be specified for each of the multiparts as well?</p>
  
  <p>Also, while specifying the content to upload, I have a file whose contents are compressed and encoded into bytes by a JSR223 Sampler and I would want this to be sent along with the request.</p>