def get_channel_info(client, channel_id):
    """Get A specific channel's information.

    Args:
        client (slackclient._client.SlackClient): SlackClient object 
            created by an API token
        channel_id (str): Slack Channel ID unique to specific slack channel

    Returns:
        str: Specified channel's information, None if fails

    Example:

        >>> import slack
        >>> from slackclient import SlackClient
        >>> token = <YOUR_SLACK_WEB_API_TOKEN>
        >>> client = SlackClient(token)
        >>> cid = slack.get_channel_id(client, "general")
        >>> msg = slack.get_channel_info(client, cid)
        >>> msg['purpose']['value']
        '<general channel's purpose displayed here...>'
    """
    channel_info = client.api_call("channels.info", channel=channel_id)
    if channel_info['ok']:
        return channel_info['channel']
    return None