public UNode getMember(int index) {
        assert isCollection();
        if (m_children == null || index >= m_children.size()) {
            return null;
        }
        return m_children.get(index);
    }
public UNode getMember ( int index ) { assert isCollection ( ) ; if ( m_children == null || index >= m_children . size ( ) ) { return null ; } return m_children . get ( index ) ; }
Get the child member with the given index. The node must be a MAP or ARRAY. Child
members are retained in the order they are added. If the given index is out of
bounds, null is returned.

@param   index   Zero-relative child node index.
@return          The child member at the given index or null if there is no child
node with the given index.