get importPath() {
    const relativeFilePath = this.filePath;

    if (this._mainFilePath === path.resolve(relativeFilePath)) {
      return this._packageName;
    }

    let filePath;
    if (this._packageName) {
      filePath = path.normalize(`${this._packageName}${path.sep}${relativeFilePath}`);
    } else {
      filePath = `./${relativeFilePath}`;
    }

    return this._slash(filePath);
  }
import path that is considered package name, main file and path prefix.
@type {string}