code: @Nonnull
    public final Schema getSchema (@Nonnull final IReadableResource aResource)
    {
      ValueEnforcer.notNull (aResource, "Resource");
  
      return getFromCache (new CommonsArrayList <> (aResource));
    }
docs: Get a cached {@link Schema} from a single resource.
  
  @param aResource
  The resource to parse into a {@link Schema}. May not be
  <code>null</code>.
  @return Either the {@link Schema} from the cache or the newly compiled one.