/**
  * Add Field
  *
  * <p>
  *
  * <p>Overidden because there can only be one vendor set
  *
  * @param field
  */
 public void addField(TagField field) {
   if (field.getId().equals(VorbisCommentFieldKey.VENDOR.getFieldName())) {
     super.setField(field);
   } else {
     super.addField(field);
   }
 }
 /**
  * Set the vendor, known as the encoder generally
  *
  * <p>We dont want this to be blank, when written to file this field is written to a different
  * location to all other fields but user of library can just reat it as another field
  *
  * @param vendor
  */
 public void setVendor(String vendor) {
   if (vendor == null) {
     vendor = DEFAULT_VENDOR;
   }
   super.setField(new VorbisCommentTagField(VENDOR.getFieldName(), vendor));
 }