mixin message-group(user)
    -
        let classes = {
            'l-message-group':          true,
            'l-message-group--compact': attributes.compact,
            'l-message-group--left':    attributes.left,
            'l-message-group--right':   attributes.right,
            'l-message-group--arrow':   attributes.arrow,
            'l-message-group--group':   attributes.group,
            'l-message-group--merge':   attributes.merge
        }
        if (attributes.class) {
            classes[attributes.class] = true
        }

    section(class=classes)
        .l-message-group__avatar.u-p-sticky-top
            +avatar= user.slice(0, 2)
        block