import six


def all_keys_are_strings_p(test_dict):
    """Check all keys in dict are strings. Returns True if so, o/w False.
    
    Args:
        test_dict (dict): Dictionary whose keys are to be checked to ensure
            they're strings.
    """
    for k in test_dict.keys():
        if not isinstance(k, six.string_types):
            return False
    return True