final ARCRecordMetaData arcData = rec.getMetaData();
// Look at ARCRecord meta data line mimetype. It can be empty. If so,
// two more chances at figuring it either by looking at HTTP headers or
// by looking at first couple of bytes of the file. See below.
String mimetype = getMimetype(arcData.getMimetype(), this.mimeTypes, url);
rec.skipHttpHeader();
reporter.setStatusIfElapse("read headers on " + url);
// Read in first block. If mimetype still null, look for MAGIC.
int len = rec.read(this.buffer, 0, this.buffer.length);
// check mimetype