ref="https://tools.ietf.org/html/rfc4648">base64</a> encoder and decoder.</p>
<p>A <a href="dart-convert/Base64Codec-class.html">Base64Codec</a> allows base64 encoding bytes into ASCII strings and
decoding valid encodings back to bytes.</p>
<p>This implementation only handles the simplest RFC 4648 base64 and base64url
encodings.
It does not allow invalid characters when decoding and it requires,
and generates, padding so that the input is always a multiple of four
characters.</p>
    </section>
    
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