public BsonTimestamp getTimestamp(final Object key, final BsonTimestamp defaultValue) {
        if (!containsKey(key)) {
            return defaultValue;
        }
        return get(key).asTimestamp();
    }
public BsonTimestamp getTimestamp ( final Object key , final BsonTimestamp defaultValue ) { if ( ! containsKey ( key ) ) { return defaultValue ; } return get ( key ) . asTimestamp ( ) ; }
If the document does not contain the given key, return the given default value.  Otherwise, gets the value of the key as a
BsonTimestamp.

@param key the key
@param defaultValue the default value
@return the value of the key as a BsonTimestamp
@throws org.bson.BsonInvalidOperationException if the document contains the key but the value is not of the expected type