public int getMinLength() {
        // This needs to be reasonably large to be able to correctly detect
        // things like XML root elements after initial comment and DTDs
        return 64 * 1024;
    }
Return the minimum length of data to provide to analyzing methods based
on the document's content in order to check all the known MimeTypes.

@return the minimum length of data to provide.
@see #getMimeType(byte[])
tika-core/src/main/java/org/apache/tika/mime/MimeTypes.java