whole_func_string: function assertPart(part, name) {
    if (part.indexOf(path.sep) !== -1) {
      throw new Error(
        '`' + name + '` cannot be a path: did not expect `' + path.sep + '`'
      )
    }
  }
func_code_string: function assertPart(part, name) {
    if (part.indexOf(path.sep) !== -1) {
      throw new Error(
        '`' + name + '` cannot be a path: did not expect `' + path.sep + '`'
      )
    }
  }
func_documentation_string: Assert that `part` is not a path (i.e., does not contain `path.sep`).