bson/src/main/org/bson/BsonDocument.java
public BsonDecimal128 getDecimal128(final Object key, final BsonDecimal128 defaultValue) {
        if (!containsKey(key)) {
            return defaultValue;
        }
        return get(key).asDecimal128();
    }
public BsonDecimal128 getDecimal128(final Object key, final BsonDecimal128 defaultValue) {
        if (!containsKey(key)) {
            return defaultValue;
        }
        return get(key).asDecimal128();
    }
public BsonDecimal128 getDecimal128 ( final Object key , final BsonDecimal128 defaultValue ) { if ( ! containsKey ( key ) ) { return defaultValue ; } return get ( key ) . asDecimal128 ( ) ; }
If the document does not contain the given key, return the given default value.  Otherwise, gets the value of the key as a
BsonDecimal128.

@param key the key
@param defaultValue the default value
@return the value of the key as a BsonDecimal128
@throws org.bson.BsonInvalidOperationException if the document contains the key but the value is not of the expected type
@since 3.4
If the document does not contain the given key return the given default value . Otherwise gets the value of the key as a BsonDecimal128 .