by <a href="dart-io/SecureSocket-class.html">SecureSocket</a>
client connections, when connecting to a secure server.</p>
<p><code>file</code> is the path to a PEM or PKCS12 file containing X509 certificates,
usually root certificates from certificate authorities. For PKCS12 files,
<code>password</code> is the password for the file. For PEM files, <code>password</code> is
ignored. Assuming it is well-formatted, all other contents of <code>file</code> are
ignored.</p>
<p>NB: This function calls <a href="dart