checkFromStringCase("google.com:25\t", 1, null, 99, false);
    checkFromStringCase("google.com:0x25 ", 1, null, 99, false);
  }

  public void testFromStringUnparseableNonsense() {
    // Some nonsense that causes parse failures.
    checkFromStringCase("[goo.gl]", 1, null, 99, false);
    checkFromStringCase("[goo.gl]:80", 1, null, 99, false);
    checkFromStringCase("[", 1, null, 99, false);

    checkFromStringCase("google.com:25\t", 1, null, 99, false);
    checkFromStringCase("google.com:0x25 ", 1, null, 99, false);
  }

  public void testFromStringUnparseableNonsense() {
    // Some nonsense that causes parse failures.
    checkFromStringCase("[goo.gl]", 1, null, 99, false);
    checkFromStringCase("[goo.gl]:80", 1, null, 99, false);
    checkFromStringCase("[", 1, null, 99, false);

    .build();
```

Client Authentication
---------------------

The above scenario is representative of most TLS set ups: the client uses certificates to validate
the identity of a server. The converse is also possible. Here we create a server that authenticates
a client and a client that authenticates a server.

```java
// Create the root for client and server to trust. We could also use different roots for each!

        return Optional.ofNullable(location);
    }

    /**
     * Returns the path type associated to the given {@code javax.tool} location.
     * This method is the converse of {@link #location()}.
     *
     * @param location identification of a path in the {@code javax.tool} API
     * @return Java path type associated to the given location
     */

            url = "file://" + url.substring("file:".length());
        }

        // So now we have an url of the form file://<path>

        // We want to eliminate any relative path nonsense and lock down the path so we
        // need to fully resolve it before any submodules use the path. This can happen
        // when you are using a custom settings.xml that contains a relative path entry

     * int.
     */
    checkNonNegative("a", a);
    checkNonNegative("b", b);
    if (a == 0) {
      // 0 % b == 0, so b divides a, but the converse doesn't hold.
      // BigInteger.gcd is consistent with this decision.
      return b;
    } else if (b == 0) {
      return a; // similar logic
    }
    /*