function shimRequire(filePath) {
  try {
    return require(path.resolve(this._moduleRoot, filePath))
  } catch (e) {
    this.logger.debug(
      "Failed to load '%s' from module root: '%s'. Stack: %s",
      filePath,
      this._moduleRoot,
      e.stack
    )
    return null
  }
}
Loads a node module from the instrumented library's own root directory.

@memberof Shim.prototype
@param {string} filePath - A relative path inside the module's directory.
@returns {*?} The result of loading the given module. If the module fails to
 load, `null` is returned instead.