code: protected PathProvider getProvider(PathUri pathUri) throws ResourceUriUndefinedException {
  
      String schemePrefix = pathUri.getSchemePrefix();
      if (schemePrefix == null) {
        // default is file://
        schemePrefix = PathUri.SCHEME_PREFIX_FILE;
      }
      PathProvider provider = this.schema2providerMap.get(schemePrefix);
      return provider;
    }
docs: This method gets the {@link PathProvider} for the given {@link PathUri}.
  
  @param pathUri is the {@link PathUri}.
  @return the {@link PathProvider} {@link PathProvider#getSchemePrefixes() responsible} for the given {@link PathUri}
  .
  @throws ResourceUriUndefinedException if no {@link PathProvider provider} is {@link #registerProvider(PathProvider)
  registered} that is responsible.