code: function getFirstVersionOfDeletion(filePath) {
      const deletionCommit = getCommitDeletingFile(filePath),
          tags = execSilent(`git tag --contains ${deletionCommit}`);
  
      return splitCommandResultToLines(tags)
          .map(version => semver.valid(version.trim()))
          .filter(version => version)
          .sort(semver.compare)[0];
  }
docs: Gets the first version number where a given file is no longer present.
  @param {string} filePath The path to the deleted file.
  @returns {string} The version number.