code: function requirementsFileExists(servicePath, options, fileName) {
    if (
      options.usePoetry &&
      fse.existsSync(path.join(servicePath, 'pyproject.toml'))
    ) {
      return true;
    }
  
    if (options.usePipenv && fse.existsSync(path.join(servicePath, 'Pipfile'))) {
      return true;
    }
  
    if (fse.existsSync(fileName)) {
      return true;
    }
  
    return false;
  }
docs: This checks if requirements file exists.
  @param {string} servicePath
  @param {Object} options
  @param {string} fileName