apollo-core/src/main/java/com/ctrip/framework/foundation/internals/io/BOMInputStream.java/BOMInputStream/skip
class BOMInputStream:  @Override
  public long skip(long n) throws IOException {
    int skipped = 0;
    while ((n > skipped) && (readFirstBytes() >= 0)) {
      skipped++;
    }
    return in.skip(n - skipped) + skipped;
  }