Gets the depth of the inheritance tree.
This metric measures the maximum distance from
Object in the type
hierarchy. It is sometimes considered that classes that are very
deeply nested may be difficult to maintain.
Note that definitions of “depth of inheritance tree” vary among systems
for computing metrics. This implementation uses the definition from Spinellis’s
book and tool (ckjm). A different tool, NDepend, defines the inheritance
depth to be the total number of supertypes, which is implemented using