Function create_form_data_payload_and_headers_with_boundary

pub fn create_form_data_payload_and_headers_with_boundary(
    boundary: &str,
    name: &str,
    filename: Option<String>,
    content_type: Option<Mime>,
    file: Bytes,
) -> (Bytes, HeaderMap)

Constructs a multipart/form-data payload from bytes and metadata with a fixed boundary.

See create_form_data_payload_and_headers for more details.