lass="block">Invokes the specific subclass to securely clear the credential value.
 Some <code><a href="Credential.html" title="interface in jakarta.security.enterprise.credential"><code>Credential</code></a></code> subclasses contain credential values
 which are inherently secure, such as tokens, for which clearing the
 credential may not be necessary.
 <p>
 For example, if the credential includes a password,
 this method would overwrite the password value.</div>
</section>
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</ul>
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</u