message: test(ngcc): remove unused `FileSystem` variable
  PR Close
diff: */
  import {encode} from 'sourcemap-codec';
  -import {FileSystem, absoluteFrom, getFileSystem} from '../../../src/ngtsc/file_system';
  +import {absoluteFrom} from '../../../src/ngtsc/file_system';
  import {runInEachFileSystem} from '../../../src/ngtsc/file_system/testing';
  import {RawSourceMap} from '../../src/sourcemaps/raw_source_map';
  import {SourceFile, computeLineLengths, extractOriginalSegments, parseMappings} from '../../src/sourcemaps/source_file';
  runInEachFileSystem(() => {
  describe('SourceFile and utilities', () => {
  - let fs: FileSystem;
  let _: typeof absoluteFrom;
  beforeEach(() => {
  - fs = getFileSystem();
  _ = absoluteFrom;
  });
  