How to use the @comunica/bus-rdf-resolve-quad-pattern.getDataSourceType function in @comunica/bus-rdf-resolve-quad-pattern

protected getSource(context: ActionContext, operation: Algebra.Pattern): Promise {
    const contextSource = this.getContextSource(context);
    const url = this.getContextSourceUrl(contextSource);
    let source: MediatedQuadSource;

    // Try to read from cache
    if (this.cacheSize && this.cache.has(url)) {
      source = this.cache.get(url);
    } else {
      // If not in cache, create a new source
      source = new MediatedQuadSource(this.cacheSize, context, url, getDataSourceType(contextSource), {
        mediatorMetadata: this.mediatorMetadata,
        mediatorMetadataExtract: this.mediatorMetadataExtract,
        mediatorRdfDereference: this.mediatorRdfDereference,
        mediatorRdfResolveHypermedia: this.mediatorRdfResolveHypermedia,
        mediatorRdfResolveHypermediaLinks: this.mediatorRdfResolveHypermediaLinks,
      });

      // Set in cache
      if (this.cacheSize) {
        this.cache.set(url, source);
      }
    }

    return Promise.resolve(source);
  }

public static async getSingleSourceType(context: ActionContext): Promise {
    const source = await this.getSingleSource(context);
    return source ? getDataSourceType(source) : null;
  }