def METHOD_NAME(styles_map):
    """
    It receives a dictionary with selector and corresponding styles array
    in a JSON similar structure and converts is to css compatible string
    Eg:
        {'div.lb-timeline': [('font-weight', 'normal'), ('font-style', 'normal')]}
    """
    styles = []
    for selector, properties in styles_map.items():
        props_map = map(lambda x: '{0}: {1}'.format(x[0], x[1]), properties)
        group_rules = dict(selector=selector, props="; ".join(props_map))
        css_group_rules = '{selector} {{ {props} }}'.format(**group_rules)
        styles.append(css_group_rules)
    return "\n".join(styles)