ers: Parameters
    :type parameters: dict

    :kwarg prefix: Name of the parent key that contains the spec. Used in the error message
    :type prefix: str

    :kwarg options_context: List of contexts?
    :type options_context: list

    :returns: Two item tuple containing validated and coerced parameters
              and a list of any errors that were encountered.
    :rtype: tuple

    Nr—