@staticmethod
def _metadata(message_tree):
    """Read message metadata
        
        HTML looks like::
            <div class="message_header">
                    <span class="user">Sender's name</span>
                    <span class="meta">Monday, August 10, 2015 at 10:40pm EDT</span>
            </div>
        
        :param message_tree: 
        :return: 
        """
    meta = {}
    for data in message_tree.iter():
        if data.get('class') == 'message_header':
            for node in data.iter():
                node_class = node.get('class')
                if node_class == 'user':
                    meta['user'] = node.text
                elif node_class == 'meta':
                    meta['timestamp'] = node.text
    return meta
