bson/src/main/org/bson/types/BasicBSONList.java
public Object get(final String key) {
        int i = _getInt(key);
        if (i < 0) {
            return null;
        }
        if (i >= size()) {
            return null;
        }
        return get(i);
    }
public Object get(final String key) {
        int i = _getInt(key);
        if (i < 0) {
            return null;
        }
        if (i >= size()) {
            return null;
        }
        return get(i);
    }
Gets a value at an index. For interface compatibility.  Must be passed a String that is parsable to an int.

@param key the index
@return the value, if found, or null
@throws IllegalArgumentException if {@code key} cannot be parsed into an {@code int}