diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index ad5fd54..300e9f2 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -29,6 +29,9 @@ jobs:
       - name: Install deps
         run: |
           sudo apt update && sudo apt install -y valgrind libcurl4-openssl-dev
+      - name: Run tests
+        run: |
+          make build test
       - name: Run examples
         run: |
           make run-examples
diff --git a/examples/advanced.zig b/examples/advanced.zig
index 3b97a9e..14ee5d0 100644
--- a/examples/advanced.zig
+++ b/examples/advanced.zig
@@ -44,7 +44,7 @@ fn put_with_custom_header(allocator: Allocator, easy: Easy) !void {
     const resp = try easy.do(req);
     defer resp.deinit();
 
-    std.debug.print("Status code: {d}\nBody: [{s}]\n", .{
+    std.debug.print("Status code: {d}\nBody: {s}\n", .{
         resp.status_code,
         resp.body.items,
     });
@@ -82,9 +82,7 @@ fn put_with_custom_header(allocator: Allocator, easy: Easy) !void {
     }
 }
 
-fn post_mutli_part(allocator: Allocator, easy: Easy) !void {
-    _ = allocator;
-
+fn post_mutli_part(easy: Easy) !void {
     const multi_part = try easy.add_multi_part();
     try multi_part.add_part("foo", .{ .memory = "hello foo" });
     try multi_part.add_part("bar", .{ .memory = "hello bar" });
diff --git a/src/easy.zig b/src/easy.zig
index 6ee1c3e..5da7af1 100644
--- a/src/easy.zig
+++ b/src/easy.zig
@@ -187,9 +187,14 @@ pub const MultiPart = struct {
     allocator: Allocator,
 
     pub const DataSource = union(enum) {
-        memory: []const u8,
+        /// Set a mime part's body content from memory data.
+        /// Data will get copied when send request.
+        /// Setting large data is memory consuming: one might consider using `data_callback` in such a case.
+        data: []const u8,
+        /// Set a mime part's body data from a file contents.
         file: []const u8,
-        // read_callback :
+        // TODO: https://curl.se/libcurl/c/curl_mime_data_cb.html
+        // data_callback: u8,
     };
 
     pub fn deinit(self: @This()) void {