```erlang 实现base 64的编码解码算法，具体细节参考RFC 20450 base64:decode("dGhpcyBpcyBhIHRlc3Qh"). -> <<"this is a test!">> base64:decode_to_string("dGhpcyBpcyBhIHRlc3Qh"). -> this is a test! base64:encode("this is a test!"). -> <<"dGhpcyBpcyBhIHRlc3Qh">> base64:encode_to_string("this is a test!"). -> dGhpcyBpcyBhIHRlc3Qh base64:mime_decode("dGhpcyBpcyBhIHRlc3Qh"). -> <<"this is a test!">> 对Data数据进行base 64编码。 base64:mime_decode_to_string("dGhpcyBpcyBhIHRlc3Qh"). -> this is a test! 对以base 64编码过的Base64数据进行解码。 ```