The reference view helps you to find memory leaks. Please note the "Show path to GC root" functionality in the incoming references for this purpose.
Compact paths are also shown for hash maps and tree maps>. This is especially important in the cumulated incoming reference view, because the internal reference structure of those collections could fragment collection content into many blocks, thereby preventing a comprehensive analysis of the incoming references. Also, hash maps are very common in reference chains and the "map key" and "map value" nodes are much more descriptive than the internal structure.