guava/src/com/google/common/io/MoreFiles.java
public static CharSink asCharSink(Path path, Charset charset, OpenOption... options) {
    return asByteSink(path, options).asCharSink(charset);
  }
public static CharSink asCharSink(Path path, Charset charset, OpenOption... options) {
    return asByteSink(path, options).asCharSink(charset);
  }
public static CharSink asCharSink ( Path path , Charset charset , OpenOption ... options ) { return asByteSink ( path , options ) . asCharSink ( charset ) ; }
Returns a view of the given {@code path} as a {@link CharSink} using the given {@code charset}.

<p>Any {@linkplain OpenOption open options} provided are used when opening streams to the file
and may affect the behavior of the returned sink and the streams it provides. See {@link
StandardOpenOption} for the standard options that may be provided. Providing no options is
equivalent to providing the {@link StandardOpenOption#CREATE CREATE}, {@link
StandardOpenOption#TRUNCATE_EXISTING TRUNCATE_EXISTING} and {@link StandardOpenOption#WRITE
WRITE} options.
Returns a view of the given { @code path } as a { @link CharSink } using the given { @code charset } .