public <T> ObjectNode getMember(String key, Function<Node, T> mapper, Consumer<T> consumer) {
        getMember(key).map(mapper).ifPresent(consumer);
        return this;
    }
The same as {@link #expectMember(String, Function, Consumer)}, but the member is optional.

@param key Key to get from the object.
@param mapper Mapping function used to convert the node value.
@param consumer Consumer to pass the found value to.
@param <T> Mapped value type.
@return Returns the node.
smithy-model/src/main/java/software/amazon/smithy/model/node/ObjectNode.java