This is a testharness.js-based test.
[FAIL] OTPCredential interface: existence and properties of interface object
  assert_own_property: self does not have own property "OTPCredential" expected property "OTPCredential" missing
[FAIL] OTPCredential interface object length
  assert_own_property: self does not have own property "OTPCredential" expected property "OTPCredential" missing
[FAIL] OTPCredential interface object name
  assert_own_property: self does not have own property "OTPCredential" expected property "OTPCredential" missing
[FAIL] OTPCredential interface: existence and properties of interface prototype object
  assert_own_property: self does not have own property "OTPCredential" expected property "OTPCredential" missing
[FAIL] OTPCredential interface: existence and properties of interface prototype object's "constructor" property
  assert_own_property: self does not have own property "OTPCredential" expected property "OTPCredential" missing
[FAIL] OTPCredential interface: existence and properties of interface prototype object's @@unscopables property
  assert_own_property: self does not have own property "OTPCredential" expected property "OTPCredential" missing
[FAIL] OTPCredential interface: attribute code
  assert_own_property: self does not have own property "OTPCredential" expected property "OTPCredential" missing
Harness: the test ran to completion.