get config() {
    return {
      targetProjectPath: null,
      // post process file
      keepInternalSources: false,
      ...this._customConfig,
    };
  }
@typedef FindImportsConfig
@property {boolean} [keepInternalSources=false] by default, relative paths like '../x.js' are
filtered out. This option keeps them.
means that 'external-dep/file' will be resolved to 'external-dep/file.js' will both be stored
as the latter