/guava/guava/src/com/google/common/io/ByteSource.java
this.sources = checkNotNull( sources) ;this.charset = checkNotNull( charset) ;
this.charset = checkNotNull ( charset ) ;
public static ByteSource empty() { return EmptyByteSource.INSTANCE; } class AsCharSource extends CharSource { final Charset charset; AsCharSource(Charset charset) { <extra_id_0> } @Override public ByteSource asByteSource(Charset charset) { if (charset.equals(this.charset)) { return ByteSource.this; }