public String getContentType() {
      return fields.get("Content-Type");
    }
The MIME type (RFC2045) of the information contained in the record's block. For example, in
HTTP request and response records, this would be `application/http` as per section 19.1 of
RFC2616 (or `application/http; msgtype=request` and `application/http; msgtype=response`
respectively).
<p/>
In particular, the content-type is *not* the value of the HTTP Content-Type header in an HTTP
response, but a MIME type to describe the full archived HTTP message (hence
`application/http` if the block contains request or response headers).
@return The record's `Content-Type` header field, as a string.
hbase-it/src/test/java/org/apache/hadoop/hbase/test/util/warc/WARCRecord.java