method with a null value for this parameter shall cause <code>getConfigProvider</code> to return null when it is
 called with layer and appContext values for which the resulting registration is the best match.</dd>
<dd><code>properties</code> - A Map object containing the initialization properties to be passed to the properties argument of
 the provider constructor. This argument may be null. When this argument is not null, all the values and keys
 occurring in the Map must be of type String.</dd>
<dd><code