Generic information about interface implemented by field type in Java

Let's suppose we have a type CustomMap<A, B> which extends CommonMap<C, D> which in turn implements Map<E, F>.

Naturally one would expect that A == C == E, but it's not always so - you can have a CustomMap<V> implementing Map<String, V> for example.

The question is, let's suppose I have a Field, and field.getType() is some interface or class implementing Map<K, V>. The type itself may be non generic, may be generic but with generic signature differing from <K, V>, etc. How go I get K and V type parameters of Map using reflection?