bson/src/main/org/bson/Document.java
public <T> List<T> getList(final Object key, final Class<T> clazz, final List<T> defaultValue) {
        notNull("defaultValue", defaultValue);
        notNull("clazz", clazz);
        return constructValuesList(key, clazz, defaultValue);
    }
public <T> List<T> getList(final Object key, final Class<T> clazz, final List<T> defaultValue) {
        notNull("defaultValue", defaultValue);
        notNull("clazz", clazz);
        return constructValuesList(key, clazz, defaultValue);
    }
Gets the list value of the given key, casting the list elements to {@code Class<T>} or returning the default list value if null.
This is useful to avoid having casts in client code, though the effect is the same.

@param key   the key
@param clazz the non-null class to cast the list value to
@param defaultValue what to return if the value is null
@param <T>   the type of the class
@return the list value of the given key, or the default list value if the instance does not contain this key.
@throws ClassCastException if the value of the given key is not of type T
@since 3.10