How to code a logical collection with both input and output items?

I am rewriting the descriptor for a Braille display with Waratah. As part of my pre-existing descriptor, I have the following:
0x05, 0x41, // Usage Page (Braille Display Page)
0x09, 0x02, // Usage (Braille Row)
0xA1, 0x02, // Collection (Logical)
0x09, 0x05, // Usage (Number of Braille Cells)
0x15, 0x00, // Logical Minimum (0)
0x26, 0xFF, 0x00, // Logical Maximum (255)
0x75, 0x08, // Report Size (8)
0x95, 0x01, // Report Count (1)
0x81, 0x02, // Input (Data,Var,Abs,No Wrap,Linear,Preferred State,No Null Position)
0x09, 0x03, // Usage (8 Dot Braille Cell)
0x15, 0x00, // Logical Minimum (0)
0x26, 0xFF, 0x00, // Logical Maximum (255)
0x75, 0x08, // Report Size (8)
0x95, 0x28, // Report Count (40)
0x91, 0x02, // Output (Data,Var,Abs,No Wrap,Linear,Preferred State,No Null Position,Non-volatile)
0x09, 0xFA, // Usage (Router Set 1)
0xA1, 0x02, // Collection (Logical)
0x0A, 0x00, 0x01, // Usage (Router Button)
0x15, 0x00, // Logical Minimum (0)
0x25, 0x01, // Logical Maximum (1)
0x75, 0x01, // Report Size (1)
0x95, 0x28, // Report Count (40)
0x81, 0x02, // Input (Data,Var,Abs,No Wrap,Linear,Preferred State,No Null Position)
0xC0, // End Collection
In short, I have a logical collection (a Braille row) grouping output items (Braille cells) with input items (routing buttons).
The standard demands that I group the Braille cells and the routing buttons under the same Braille row logical collection.
How do I write this in Waratah?

Start with the Waratah descriptor syntax and the Braille row example included in the issue. No file or test is named, so first locate the relevant logical-collection and input/output-item handling, then verify that the documented approach produces one collection containing both item types.