src/vs/workbench/common/editor.ts/EditorResourceAccessorImpl/filterUri
class EditorResourceAccessorImpl:	private filterUri(resource: URI, filter: string | string[]): URI | undefined {

		// Multiple scheme filter
		if (Array.isArray(filter)) {
			if (filter.some(scheme => resource.scheme === scheme)) {
				return resource;
			}
		}

		// Single scheme filter
		else {
			if (filter === resource.scheme) {
				return resource;
			}
		}

		return undefined;
	}