@Override
            public K getKey() {
              return key;
            }
Reads a snapshot file.

@param <K> the key type
@param <V> the value type
@param snapshot the snapshot file
@return the snapshot iterator

@throws IOException error reading the snapshot file
@throws ClassNotFoundException unable to deserialize entry
geode-core/src/main/java/org/apache/geode/internal/cache/snapshot/GFSnapshot.java