rations (with <a href="dart-io/File/open.html">open</a>),
or convenience methods such as <a href="dart-io/File/readAsString.html">readAsString</a>,</p>
<p>Most methods in this class occur in synchronous and asynchronous pairs,
for example, <a href="dart-io/File/readAsString.html">readAsString</a> and <a href="dart-io/File/readAsStringSync.html">readAsStringSync</a>.
Unless you have a specific reason for using the synchronous version
of a method, prefer the asynchronous version to avoid blocking your program